Preservative Compounds.
Within a few years some valuable methods of keeping meats, fish, oysters, fruits, fruit juices, milk, butter, etc., in a healthful, nutritious, and palatable condition for a considerable time past the ordinary period of their decay have been discovered. In the following treatise we give the results of the most patient research in securing all the latest and most valuable information in regard to this important subject.
We will not deal with processes which necessitate complicated apparatus or which require almost impossible chemical combinations, but we will explain inventions which have undoubted value combined with as much simplicity in the preparation as the circumstances will permit.
Of all the anti-septic agents used for the purposes mentioned boracic acid is the favorite, and salicylic acid next in choice. Various other anti-septic agents are used and combined in different ways, according to the results of experiments. They are applied either by immersion, coating, injecting, vapors, etc., according to specified instructions.
Prof. Frederic S. Barff of Kilburn, England, it seems was the first to combine boracic acid with glycerine, and to produce a preservative compound known as boroglyceride, which is soluble in water and alcohol. As boracic acid is but slightly soluble in water and other common solvents this combination with glycerine—which is also a useful agent in arresting the growth of germs—is peculiarly valuable. It is tasteless and inodorous and imparts no disagreeable taste or odor to the substance being treated. Solutions of the compound may be applied to the preservation of all organic substances, either animal or vegetable. The process was patented in England in 1881 and in the United States in 1882.
To prepare boroglyceride, glycerine is heated to near its boiling point and boracic acid added until it ceases to be dissolved, the proportions being about 92 parts by weight of glycerine to 62 parts by weight of boracic acid in chrystals. Maintain the mixture to a temperature of about 200 deg. centigrade as long as water is given off. When the mass cools it becomes a yellowish, transparent, glacial substance, tough and deliquescent. This dissolves in water, but when boiled in large quantities of the same it is decomposed into glycerine and boracic acid. In order to employ the compound prepare a solution either in water, alcohol, or other suitable solvent and immerse in or impregnate with such solutions the organic substances to be operated upon. Solutions may be prepared of various degrees of strength, but it has been found that a solution consisting of 1 part by weight of the compound and 40 parts by weight of water will give good results; but other desired proportions may be adopted.
Prof. Barff, the inventor of the boroglyceride process, read a paper before the Royal Society of Arts, London, in regard to his method of preserving food. The date of the reading is not at hand, but it is supposed to be slightly prior to May 13, 1882, on which date it was printed in the Scientific American Supplement. Although quite lengthy the paper contains so much interesting data and light upon the subject that we reproduce it almost entirely, together with remarks by other eminent gentlemen who were present at the meeting:
“This evening I have on the table specimens of food which have been kept for longer or shorter periods, as they are intended to illustrate various applications of this preserving material. As you know oysters are imported very largely in tins. They are cooked at a high temperature and hermetically sealed. The high temperature to which they are exposed necessarily causes a loss of flavor, and it is generally remarked that tinned oysters are not a success. * * * I have oysters on the table which were opened on the 3d of December in last year. I will ask you to taste them and see in what condition they are, and I would also remind you that they have not been kept in hermetically sealed tins, but simply in corked or stoppered bottles; hence this method of preserving oysters is cheaper than the other, and I maintain that it is more effective, because their natural and fresh flavor is preserved. I am informed by a friend in Jamaica that he has sent me some Jamaica oysters and other things—I trust they will be here in time for me to submit them to you this evening.
“Another substance, the perfect preservation of which is very important, is cream, both for home use and for exportation. Cream in London costs from four to five shillings per quart; it can be bought in country places for two shillings, and even for less. This preservative substance will keep cream for months perfectly good and sweet, having its full flavor; so that it would be quite possible to send it in quantities from the country, and its sale need not be pressed as it need not be used immediately. I have regularly every week, except during the holidays, brought with me from Beaumont College, near Windsor, where I lecture, a quart of cream treated with one ounce of the boroglyceride; it has always kept perfectly good even in the hottest weather. I have done this for a year and a half; a near relative has taken the greater part of this regularly for the time stated, and this proves conclusively that there is nothing at all injurious to health in the compound. I see a gentleman present here to-night who is connected with that college as a professor of natural science, and he will, in the discussion, be able to give you very valuable information as to the material and as to its perfect wholesomeness. Last month I sent some cream to the Rev. J. Ryan, a Jesuit priest in Jamaica, and I have received a letter from him, from which I will read you an extract:
‘26 North Street, Kingston, Jamaica,
‘February 24, 1882.
‘The cream which you sent was used by eight of us in coffee, and was pronounced to be wonderfully good. Next morning it was taken in preference to a beaten egg, by the captain of H. M. S. Tenedos, to his coffee.’
“Last year I sent some Devonshire clotted cream, which I prepared myself, to Zanzibar, on the east coast of Africa. The climate here is very hot; fresh food will only keep a few hours. This cream had to pass through the hot climate of the Red Sea. I will read an extract from a letter written by a lady who received the cream:
‘Universities Mission To Central Africa,
‘Mbweni, Zanzibar, March 8, 1881.
‘The Devonshire cream you sent us was quite a success. I received it last night. Fortunately the Bishop and Miss A—— came to Mbweni, to-day, so we had it for dinner. That I might have everything correct I opened a pot of raspberry jam which we had from London a long time ago. The Bishop said it had kept perfectly, but had not quite the rich flavor that it has when quite fresh; he has been used to it in Devonshire. Every one pronounced it most excellent. We sent some in to Mrs. H——, and were surprised at her sending for more, for she seldom eats half anything we send her. She did not know what it was, but she said she had never had anything here she enjoyed so much.’
“A year ago I sent some cream from Beaumont College dairy to the Rev. Thomas Porter, the head of the Jesuit Mission in the West Indies. He states that the cream was as good as any he had eaten at home, that he gave it to several strangers to eat, and that they would not believe that it came from England. These experiments and these testimonies prove conclusively that this compound will preserve cream. I shall this evening show you specimens. It is easy to send cream in good condition to the tropics. A great objection to condensed milk is that it is always too sweet. The boroglyceride will preserve condensed milk, and will give it no flavor at all. My friend, the Rev. Thomas Porter, sent me some articles preserved with the material which I sent him from England. They arrived about June in last year. Some raw, fresh turtle came quite fresh. It was cooked and eaten by several persons, who said it was quite fresh and good, and had the flavor of fresh turtle. At my own house I had turtle cutlets fried; they were perfectly good, and tasted like turtle. Another article which Father Porter sent me was an uncooked Jamaica pigeon; it was roasted at Beaumont College. I divided it and brought half of it home It was tasted by twelve people, who all pronounced that it was perfectly good, and had the true pigeon flavor. In the same parcel came some green sugar-cane, fresh tamarinds taken direct from the tree, fresh limes, and the juices of two different fruits. All were fresh, and were tasted by gentlemen who had lived in Jamaica, who all declared that they had all their own peculiar flavors. On the 3d of September, 1881, another box was sent me from Jamaica, containing sugar-cane, guavas, fresh ginger, and turtle; the turtle had come to grief, because it was not properly treated on the other side; the cane, guavas, and fresh ginger have been tasted by those who have lived in Jamaica, and have been pronounced to have their true flavors.
“Ordinary milk cannot be kept good for a long time, especially in hot weather. If milk were concentrated in this country, and heated with the boroglyceride, carriage would be saved, and the milk might be kept good and fresh for a fortnight and more; all it would require would be to reduce it again to its original strength. If fresh milk be treated with this preservative it can be set for cream for several days, even in hot weather. The cream which rises will keep, and the skim-milk will remain sweet for several weeks; this I have tried in the dairy at Beaumont College. From the cream so prepared butter was made, and was kept for several weeks without a particle of salt, and was eaten by members of the college. I also wish to show another method by which meat can be preserved and cheaply transported. In South America, about Buenos Ayres and the River Platte, many cattle are killed simply for the hides and fat; the flesh is thrown away. Now, if this flesh were cut up in small pieces, and put into the preserving liquid for a night, it would, even in that hot climate, keep good for some time. It could then in a few hours be dried in the sun, packed in casks, and sent to this or to other countries. I have a specimen of beef treated in this way. It was put into the solution on Jan. 19, 1882, dried Feb. 1, and has lately, within a few days, been boiled, and here is the resulting beef tea, which has not in any way been flavored. I have also small quantities of beef juice here preserved in bottles. The juice was expressed and has been kept raw. Raw beef and mutton juice is recommended by medical men in many conditions of the digestive system. I administered it to a near relation for six weeks, and the juice was preserved good by my material. In the case referred to the effect was very satisfactory. It appears to me to be a most important matter that soup meat, and meat for potting and stewing, should be sent to this country in the way I propose. The supply would be large, the prices low, and the profits highly satisfactory, and it would greatly relieve the meat market, because a very large quantity of fresh meat which is now used for soup could be employed in other ways. It has been remarked to me: ‘But would you get people to use it?’ I think, to begin with, that if proprietors of hotels and heads of large public institutions, workhouses, and hospitals could be shown that for half the cost they could have equally good soup and soup stock, they would willingly use it, and from thence it would come into private use. I have specimens to show the effect of boroglyceride on fish. Here are sprats which have been kept for a year; they are dry, but perfectly good and eatable; also some preserved fresh since Jan. 13, 1882. You will be able to judge of their appearance and flavor. I have also herrings and a piece of skate which have been preserved for the same time. If fishmongers had a tank of this solution they could, at the end of the day, put their fish in it, and take them out when required. Bloaters, when lightly cured in hot weather, do not keep good many days; if a small quantity of this stuff was used with the salt, they would keep good for months. The same may be said of smoked salmon. That which is very salt costs 9d. per pound, but the mild cured kinds cost 3s. 6d. to 4s. per pound. All could be mildly cured if this material was used with the other curing substances. As an adjunct in curing mild hams and bacon it would be of great use, for these, when cured lightly, would not go bad, as they often do in the summer time. What I have said as to the temporary preservation of fish by fishmongers applies equally to the preservation of meat and fowls by butchers and poulterers.
“It is justly complained of that the Australian cooked meat is overcooked. If it were for a short time dropped in this preservative solution it would keep perfectly well after being lightly cooked, even underdone. I have a piece of beef which was dipped Feb. 28 and boiled on March 9. It has been left in its own liquid, it was not flavored, and no salt was added. Here, too, is a vast field for the application of the process. Here is also lobster which was taken out of the shell Feb. 1, and here are two lobsters in their shell which were immersed on the same day.
“I now wish to draw your attention to a parcel from Jamaica, which has just arrived, and from which I am able, I am happy to say, to show you specimens which must be of interest. In a jar on the table is some fresh turtle, which I had simply cooked. I thought it better so to present it to you rather than raw. There is also a Jamaica pigeon, also just cooked here, and a vol au vent, which I have had made from oysters which were sent open in the preserving stuff from Jamaica. These specimens will prove conclusively that food sent from a tropical climate retains its freshness and delicate flavor. I have reserved one of the pigeons raw, that you may see in what state it arrived. Some mutton was shipped to me from the Falkland Islands at the beginning of last August; a piece of it is uncooked on the table. I have also had a piece stewed, which you will be able to taste; this has of course passed the tropics. Through the kindness of my friend Mr. Haffenden of the ‘Andaluzia,’ in the Strand, who owns vineyards in the southwest of Spain, I can show you some perfectly fresh sardines which he had placed in the preserving fluid several months ago in Spain, and which he brought with him. You will yourselves judge of their condition; I will only remark that they have the peculiar fragrance of that delicate fish, and will it not be a boon to have a supply of this fresh delicacy at a moderate cost?
“You will also see, and I hope taste, a pigeon pie. The pigeons and the steak have been preserved raw in stoppered bottles since the 21st of last November and the eggs since the 4th of July, 1881. I will also call your attention to a tongue which I myself placed in the solution Feb. 9 in this year, with some garlic, sugar, and juniper berries, my object being to show that salt can, if desired, be dispensed with. You will doubtless find that it will require salt; but you will readily infer that hams, tongues, etc., can be made just as salt as one pleases, and will yet keep perfectly sweet, in fact sounder, than those cured only with salt. This tongue was boiled out of pickle. I exhibit two shoulders of mutton, one cooked, the other raw; they are from sheep killed Jan. 10, 1882. Also a piece of beef preserved on the same day; this when you have inspected it shall be cut in slices and broiled. You will see some sausages, both cooked and uncooked; they were made for me by Mr. Bowron, poulterer, of Paddington, early in July last, before I went to Carlsbad. I took some with me to that place, and they were there eaten and pronounced good. These are some of the same lot; they were made as follows: The meat was chopped, put into the preserving fluid for one night, and then mixed with the other material in the ordinary way. They have been kept since in an earthenware jar; they have, therefore, been made more than nine months. I may remark that the bread in these sausages was not treated, and therefore it has become slightly sour, but the pork has kept perfectly fresh. I have also some other sausages which I bought Jan. 12, and at once preserved; these having been steeped, the bread has not turned in the slightest degree sour.
“Mock turtle soup, bought ready made from a confectioner’s shop in Oxford street, Jan. 25, treated with the preservative stuff, has remained quite good and unchanged in flavor.
“There is also a specimen of gravy soup made in October last, and some vermicelli soup made about three weeks ago. The preservative action of boroglyceride in cooked foods is, it seems to me, of great importance to hotel-keepers, confectioners, and restaurant proprietors, as it will enable them to buy large stocks when certain articles are cheap, and from the specimen I show of cooked beef you see it remains quite moist, as it can be kept, without getting sour, in its own gravy and under a layer of its own fat. To prove that articles can be kept and dried without losing their flavor, I had some partridges treated and dried last February twelvemonth, and I exhibit some soup made from two of these birds. The other articles on the table are one raw and one roast fowl, bought Jan. 17; one raw and one roast pheasant, bought Feb. 5; one rabbit boiled, bought Jan. 17. There are also from Jamaica a green lime, some fresh tamarinds, and some pieces of fresh ginger. * * *
“I thank you, ladies and gentlemen, for the patient hearing you have given me.”
DISCUSSION.
The Chairman said the paper was marked by the clear and philosophic way in which the subject was treated, and before inviting discussion upon it he would mention shortly his own experience of the process, the only interest of which was that it was quite independent of Prof. Barff. When he was asked to take the chair he communicated with Mr. Barff, and inquired what the process was. Mr. Barff kindly sent him a specimen of this substance, which he melted, and put some of it into one-half of a pint of cream. The other half very soon turned sour, and had to be thrown away, but that to which the substance was added was perfectly fresh that morning. He was confirmed in the opinion of its freshness by the cook, though she said there was a very slight tartness perceptible, by which she could distinguish it from fresh cream. He had also tried another experiment on meat which was chopped very fine, and divided into two parts; to one part he added merely tepid water, to the other, tepid water to which one-sixteenth of its bulk of this compound had been added. This was left on the meat for eighteen hours, and then filtered off through muslin. Several days ago the portion which had no preservative was very offensive, but the other portion was that morning perfectly free from any odor whatever.
The Rev. J. L. Dobson said he had had the pleasure of being associated with Mr. Barff in most of the experiments he had detailed, and might therefore anticipate his reply to one or two points raised by Dr. Graham. An experiment which was tried for some time in a large school would answer the question of wholesomeness. At the Beaumont College, Windsor, there was a large staff of teachers and over 200 pupils, and during the hot weather of last summer the dairymaid was very much annoyed at the milk turning sour, and applied to him to see if he could do anything to counteract it. He handed her some 14 or 15 lbs. of this material and during the whole of the hot weather and well on into September it was constantly used, and the milk was preserved; but the method was not detected by any one, either by the younger members or by those who might be expected to be more critical. No ill effects were observed by the medical officer or by individuals. From his own experience he thought the aroma was very well preserved throughout. For instance, in oysters which had been preserved over three months there was the characteristic aroma of the fresh oyster; mutton could be easily distinguished from beef, and the peculiar smell of the turtle was also very distinct. They had not yet tried beer with so much fullness as other articles, but about nine months ago a small quantity was treated and left exposed to the air, with only a loose stopper of cotton wool. It did not grow cloudy in the ordinary way, but owing to the severity of the experiment, and perhaps to not sufficiently treating it, after four months it lost all flavor, became extremely flat, and a slight fungus appeared.
Dr. Thudichum had listened with great pleasure to the paper, and had no doubt if the application of the invention could be effected on a large scale it would be very useful. He had some experience with regard to a portion of the ingredients used, viz.: boracic acid, though he had none of this beautiful new compound. It might not be known to the meeting that boracic acid had been used for a great many years for preserving food, and in fact many of them in summer time had their milk well dosed with it. It had been sold to milkmen in London for years under the name of “aseptin.” He had tested it in 1865 and found a great many of those effects which Mr. Barff described. For instance eggs were beautifully preserved, and steak immersed in the solution did not become either mouldy or decomposed, but on the contrary appeared to retain its flavor. A variety of other things, such as cheese and cream, were for a long time preserved by this application of aseptin. He hoped the addition of the glycerine would increase the power and prevent some drawbacks which would otherwise stand in the way of boracic acid alone as a preservative of raw or cooked meat.
Prof. Barff, in reply to the various questions which had been asked, said he had used salicylic acid and had found it useful in preserving food, but for several reasons discontinued further investigations, one being on the score of its unwholesomeness, and he found that his views on that point had been borne out by the action taken by the French Government. Dr. Graham had asked him about flavor; he had given Dr. Graham a few days ago some specimens of preserved fish, which he said had lost their flavor, but that would not be found to be the case with the box of sardines. The herrings had been kept in an open vessel exposed to the air ever since the day they were put into the liquid, and therefore it was not surprising that they had lost their flavor. If they would try any of the things which had been tinned, not soldered up, but such as the Jamaica pigeons, which were in a common corked bottle, it would be found that the aroma and flavor were retained. The only thing requisite was to keep the vessel so as to exclude the air, as you would with tea or coffee. Dr. Thudichum made some very interesting remarks which there was not time to refer to at length, if he were competent to do so, but not being a medical man he could not enter into medical questions. As to the wholesomeness of the compound, however, he might say that he had taken large quantities of it himself and it had never done him any harm; and a near relative had taken an ounce per week regularly for a year and a half, without any ill effect—a person, too, not very strong or of good digestive powers. The boys and teachers of Beaumont College drank milk preserved with it without distinguishing the taste or suffering any ill effects. He knew there were medical opinions in favor of boracic acid, and one physician he was acquainted with used it as a medicine. If it were at all unwholesome he certainly should not recommend it, but he did not think there was the slightest fear. As to boron getting into the system, it was not boron which was used, but oxide of boron; but even if it did—and he should not be surprised if traces of boron were found in the excreta—it did not follow that any harm was done. There were many things which went through the system without injury; for instance, silica, of which most people took a great deal in the twenty-four hours. As to the cost of the process the cost per gallon, as far as he could tell—he could not tell exactly—would be under 1s.—perhaps 8d. or 9d.—and a gallon would affect an enormous quantity. Most of the articles on the table were put into one pan of solution, and the cost of the whole stuff was about 9 1/2d. Should the process be adopted commercially experiments as to the cost would be most carefully made and the results published. A joint of any size could be soaked; the only thing was to give it plenty of time. You might soak a piece of beef of twenty pounds, forty pounds, or fifty pounds; or you might use an injecting syringe, such as butchers employed for salting meat quickly, and the meat so treated would keep for a week or a fortnight perfectly good, but he did not think it would keep well enough to pass under a tropical sun. In order to do that you must inject by the aorta, by means of a force pump, so as to send the liquid into all the interstices of the flesh. As to the proportions, 1 in 20 was the strongest he used, and 1 in 60 the weakest; for preserving meat 1 in 50 answered perfectly well—1 lb. of the compound added to 50 lbs. of water. The bottle should be put before the fire until melted, and then poured into hot water, and it would dissolve. With regard to preserving morbid specimens he thought it would answer perfectly well. He had had some practice in morbid anatomy, and he might say that, for the injection of bodies to be used for anatomical purposes it would keep them perfectly sweet. It should be injected by the aorta in the usual way before injecting with the red wax. In reply to Mr. Dipnall he would say that the compound penetrated right through into the innermost parts of the meat. If you had an earthen pan and put into it 1 lb. of this and 50 lbs. of water, and placed in it a joint which came home on the Saturday night in hot weather, you could take it out the next day and it would keep perfectly for a fortnight. Of course it took time to penetrate into the meat, but the first superficial penetration stopped the injurious effects of germs which set up putrefaction. Another important fact was this: if you had a roast leg of lamb, perfectly good, but did not eat it all, and put it away in hot weather, it would turn sour, but if it had been treated in this way it would not; it would keep for six months without going sour. By adding a small quantity from time to time, which you could only learn by experience, the bath would keep perfectly fresh and effective, though it would be found after a time to get rather dark colored. That arose from the juice of the meat, and the advantage of this process was that you need not throw it away, as you must brine, but could boil it down into very good soup. In conclusion he would only ask his hearers to read the paper and discussion carefully when published, and he was sure any one would be able to carry out the process.
The Chairman, in proposing a hearty vote of thanks to Prof. Barff, said the process he had described was remarkable for its great simplicity and the ease with which it could be carried out. Any cook could readily apply it.
The vote of thanks was carried unanimously.
An Improved Boracic Acid-Glycerine Compound.
The following is the invention of an American, William S. Fickett of Rochester, N. Y., and is an improved process of combining boracic acid with glycerine for preservative purposes. (Patent No. 285,350.)
“My invention consists in a new mode of producing a new preservative compound from boracic acid and glycerine, as hereinafter described. Heretofore by one method* such a compound has been produced from these ingredients by heating glycerine to near its boiling point and adding boracic acid until it ceases to be dissolved, and maintaining that mixture to a temperature of 200 deg. centigrade as long as water is given off, etc.
* Doubtless the Barff process—[author].
“Now my process consists in taking equal quantities of glycerine and crystallized boracic acid, placing the same in a closed or sealed vessel, and then applying heat at about 300 deg. Fahrenheit for about two hours, which causes the boracic acid to dissolve and blend with the glycerine. On cooling it forms without loss of weight into on opalescent semi-solid, freely soluble in cold water, entirely devoid of bitter or metallic taste, and communicating no objectionable taste to butter or like delicate foods. When thus produced it is an unfailing preventive of fermentation and decay in animal and vegetable matter or fluid compounds.”
The following is a different process of using boracic acid, and explains itself:
James Howard, Philadelphia, Pa.; composition for preserving foods. (Patent No. 276,246.)
“I have discovered a method of obtaining a chemical compound of boracic acid for the production of which neither solution nor the employment of heat is necessary, the salt being formed by the union of the component substances in a dry state, so that the difficulties of solution and of loss through volitization is avoided. Moreover the compound has anti-septic properties distinct from those of the acid, due to one of the other elements thereof, and is tasteless.
“I take preferably not less than 5 parts by weight of pure boracic acid in crystals, and add thereto 1 part of pure phosphate of soda. The ingredients are mixed together dry, in a mill or other suitable grinding apparatus, and as the chemical reaction between them progresses the whole, or practically the whole, of the acid crystals lose their structure, and the mass can be ground until it assumes a pasty or doughy condition. The result is boro-phosphate of soda, containing more or less free boracic acid, according to the excess thereof used above the proportions given. The moisture yielded by the chemical reaction is evaporated at the ordinary temperature by exposure to the air without loss of boracic acid, and the dry amorphous salt thus produced is readily ground. It may be used either as a dry powder or may be dissolved in water and applied in the usual modes to the substances to be preserved. If desired other substances, such as salt and saltpeter, may be added to the boro-phosphate compound, and the whole mixed thoroughly by regrinding.”
Preservation of Butter, Lard, Etc.
The following process is the invention of Mr. William Pitt Clotworthy. (Patent No. 284,184.)
The process consists of incorporating with the fat, which may consist of butter, lard, or other grease, a sufficient amount of paraffine. Paraffine is non-oxidizable, without taste or odor, and, as the inventor claims, it is perfectly harmless when used in this manner, just as beeswax is swallowed with honey, although not in such large proportion. Tons of paraffine are manufactured yearly into chewing gum and chewed harmlessly by thousands.
In preserving butter the process is as follows: Take 1 ounce of fresh unsalted butter and incorporate with it 1 ounce of paraffine, and thus form a jelly, and then thoroughly mix this amount of jelly with 1 pound of butter.
In preserving lard combine the paraffine as follows: When the lard is ready to be drawn off from the rendering kettles, and while still hot, add 1 ounce of paraffine to each pound of lard and stir the mass thoroughly.
Compound for Preserving Food.
Theodore L. Corwin of Marathon, N. Y., has invented the following. (Patent No. 253,983):
The invention relates to the class of compounds used to preserve in a healthful state such articles of food as meats, fish, milk, eggs, butter, oysters, cider, and also to be used as a disinfectant and to arrest putrefaction.
“I take of nitrate of potassium, of salicylic acid, and of chloride of sodium, each 1 ounce. These should all be in powder and dissolved in 1 quart of water. Then add 1 drachm of hydrochloric acid previously diluted with 1 ounce of water. To preserve meat immerse for twenty minutes in the hot solution, after which let it drain for one hour; then pack in a well-closed vessel. For the preservation of fish use the same as for meat, only the solution should be allowed to become cold before using. To keep oysters stir into them 3 ounces of the solution (cold) to each gallon of oysters. Cider will be kept sweet if there is added to each barrel 1 quart of the solution immediately after the cider comes from the press. Milk to be kept sweet should have the powder first named, viz.: nitrate of potassium, salicylic acid, and chloride of sodium, each 1 ounce, added to every 16 gallons. As a disinfectant the solution should be sprinkled freely around the place or places to be disinfected. To prevent putrefaction the solution should be copiously applied to the object treated.”
Fruit-Juice Preservatives.
An Ohio inventor has patented a process for preserving fruit juices such as cider, wine, etc., which he says, if treated according to his directions, will keep unchanged for years:
“The juice is taken before fermentation takes place and boiled, all scum is carefully skimmed off, and then the liquid, while still hot, is filtered through a compound of partially pulverized charcoal, crushed mustard seed, and ground sassafras root. The filter should be covered with fine woven wire, outside of which should be fastened a flannel cloth to catch all escaping sediment. To every gallon of juice to be filtered there is placed in the filter 2 ounces of charcoal, 2 scruples of crushed mustard seed, and 6 drachms of ground sassafras root. After filtering it is again boiled, and if any scum or impurities appear on the surface they are removed, when the juice is to be bottled, corked tightly, and should be left for one year.”
Schaumberg & Dillon’s method of preserving fruit juices consists in bottling and sealing the juices, and then heating the bottles to 170 deg. Fahrenheit for thirty-five minutes. The juices are put in bottles and are immediately corked and wired securely, and then submerged in a water bath to a depth of about 1 inch above the bottles.
The advantages of this process are that the fruit juices will remain sweet indefinitely, will not ferment, and are free from all deleterious matter.
Smoke or Vapor Preserving Compound.
Rebecca A. McDaniel of Burr Oaks, Ia., has patented the following, which is one of quite a number of this class of preservative processes:
“In preserving different articles, such as fruits, meats, and other edibles, I subject them for a proper time—differing with different articles—to the fumes arising from burning the compound. This may be accomplished by confining the articles to be treated in a chamber in which the compound is being burned.
COMPOSITION.
| Salicylic acid1 | ounce. |
| Sulphur2 | pounds. |
| Pulverized orange peel 1/4 | ounce. |
| Ground cinnamon3 | ounces. |
“This compound well mixed will burn slowly and generate fumes or vapor which have a peculiar action in the preservation of fruits, butter, milk, pies, bread, eggs, and all kinds of cooked or uncooked food. In treating meats add nitrate of potash, 4 ounces.
“Treatment: Provide a box or other chamber with shelves upon which the articles to be treated may be placed. Within the chamber, properly closed, I burn a suitable quantity of the compound, allowing the fumes to bathe the articles to be treated. The compound is of a quality that will burn slowly by reason of its peculiar composition, and it may be burned with fuel other than it contains.”
Salicylic Acid as a Preservative.
Salicylic acid, aside from its remedial value, is used largely as a preservative, either in a dry state or in the form of a solution in water or alcohol. Salicylic acid is a white, dry, crystalline powder, devoid of smell or taste, undergoes no change when kept in store, and is neither inflammable nor volatile. It can be procured in almost any drug store, and since 1874 a new process in its manufacture has cheapened it in price and placed it within the reach of all.
Medical authorities agree in considering the daily consumption of 1 gramme as being not only perfectly inoffensive, but decidedly beneficial to health. An individual living on a salicylated diet would not absorb so much of the salicylic acid per diem as that which is prescribed to be taken for the prevention of epidemics and other ailments, such as gout, rheumatism, catarrhal affections, etc.
The proportions in which salicylic acid dissolves are:
One part by weight in 300 to 500 parts of cold water.
One part by weight in 18 to 20 parts of hot water.
One part by weight in 50 parts of glycerine.
One part by weight in 3 parts of absolute alcohol.
In rum, brandy, wine, cider, etc., it dissolves according to their respective strengths and temperatures.
Note.—By contact with iron in any form salicylic acid takes a violet color.
This must be noted, especially when treating milk, etc., if contained in metallic vessels. The only bad effects will be simply slight discoloration.
MEAT.
It is a well-known fact that, especially in hot weather, meat, poultry, and game, although apparently quite fresh, prove, on closer examination, or often only when cooked, to be tainted and of bad odor. This can be entirely removed by either watering and washing the meat in a lukewarm solution of salicylic acid (three to four teaspoonfuls of acid to two quarts of water), or by adding a small pinch of the dry acid in powder, during the cooking.
To keep meat for several days from becoming high or tainted:
Place it for twenty or thirty minutes in an aqueous solution of 8 drachms of salicylic acid to one gallon of water.
Rub into the surface of the meat some dry salicylic acid, particularly about the bony and fatty parts; the meat to be afterward cleaned before cooking as usual.
Although the raw meat treated with the acid turns slightly pale on the surface it suffers no change whatever internally. Meat thus treated with salicylic acid requires, also, less cooking to render it tender.
PURE MILK.
A third of a teaspoonful (or, if the temperature be high, a little more) of the solid acid to a quart of milk delays the process of curdling for thirty-six hours, without influencing its property of yielding cream.
BUTTER.
Washed with an aqueous solution (four drachms of acid to a gallon of water), or kept in it, or wrapped in cloths soaked in this water, keeps fresh for a very long time. Butter already rancid can be improved by treatment with a stronger solution (8 drachms of acid to 1 gallon of water), followed by washing in pure water. The bad smell often arising in salted butter is entirely prevented by addition of the acid.
JAMS OF ALL KINDS, JELLIES, PRESERVES, AND PICKLES.
Of every description, made in the usual way, but with the addition of about 1 drachm of salicylic acid to every 4 pounds of the preserve, will keep sound with absolute certainty for a much longer time, fermentation and mouldiness being prevented. Under exceptionally unfavorable circumstances, such as hot pantries, a little of the dry acid should be sprinkled on the top of the vessel or preserve pot. A tightly-fitting piece of blotting paper, previously saturated with a concentrated solution of salicylic acid in spirit, brandy, or rum, and placed on the top of the preserves will also greatly aid in keeping them.
NEW-LAID EGGS
Can be kept for a very long time by being placed for half an hour in a cold, saturated, aqueous solution of the acid, then allowed to dry in the air, and, as usual, kept in a cool place. Some prefer to coat them by dipping them in melted paraffine after they have been treated in this manner. (Use no straw or hay in packing eggs.)
THE YOLK AND THE WHITE OF EGGS
Are most effectually preserved for a long time by the addition of 1/2 to 1 ounce of the acid per 20 pounds of these substances. It is also well to place a paper soaked in the salicylic acid solution on the top of them, which greatly enhances the preserving effect.
In the manufacture of vinegar, salicylic acid is also of great importance to prevent false or excessive fermentation, putridity, etc.
WINE.
With respect to wine the experiments of Prof. Neubauer of Wiesbaden have proved that the introduction of the acid for the preservation of wine marks an era of great industrial progress, as it energetically prevents, even when used in very small quantities, the formation of mould germs and other circumstances which are injurious to wine, while it absolutely arrests secondary fermentation, cloudiness, etc. As wine differs very much in its constitution the requisite quantity of salicylic acid must be found out by practice in each particular case. About 1/4 to 3/4 of an ounce per 50 gallons will be found sufficient for most wines. In using the salicylic acid for this purpose it is recommended to make a strong solution of it in pure spirit, perfectly free from fusel oil, and then to add of this solution as much as may be requisite.
If in addition to this the casks are washed out with an aqueous solution of the acid it will prove of great service, and all other agents at present used for this purpose will soon be abandoned. The larger the amount of sugar in proportion to the alcohol the more salicylic acid will be required. The addition is best made when the wine has attained its full ripeness. The effervescence of wine in spring, or after carriage in warm weather, will at once be stopped. The salicylic acid kills all kinds of germs, and destroys the growth and action of any yeast which may still be present; it is therefore of incalculable value in effectually preserving wine, and as a preventive of the deterioration to which this liquid is subject.
Must, fresh from the press in autumn, can be kept without fermentation perfectly fresh, bright, and sweet for six to eight months by the addition of 1 to 1 1/2 ounces per 50 gallon, or of 3/4 ounce per 100 bottles. Sparkling Must requires an addition of 6 to 7 ounces of salicylic acid per 100 gallons. In the same manner all kinds of fruit-wine which, as is well known, soon turn sour, can be preserved by the addition of a similar quantity of salicylic acid. Must kept still for transport can at any time be set into fermentation by a slight addition of carbonate of soda and fresh yeast.
BEER.
Experiments made upon a large scale have placed beyond a doubt the remarkable properties of salicylic acid as a preventive of secondary fermentation and acidity in beer, and as a preservative of beer in a sound condition when sent out or exposed to the noxious influences of warm cellars, change of temperature, etc. The amount of salicylic acid required to produce the best effects in preserving beer varies according to the quality of the malt liquor; but half an ounce per barrel of 36 imperial gallons will be very generally found to answer the purpose well. The addition of the salicylic acid delays secondary fermentation in stock and export beers, which may then be kept for any length of time without becoming unsound or of unpleasant flavor. Less than a quarter ounce of the powder of salicylic acid per barrel of boiling wort strewn into the same while turning out will destroy or suspend the vitality of the false ferments, especially that of the lactic ferment, in the fermenting vats, and this not only without injury to the yeast cells, but keeping them free from parasitical growths. In this manner the fermentation will take a steadier course and enable the liquor to attain its perfection during the ensuing still fermentation in the cask, into which another quarter ounce or more of the acid is to be given per barrel a fortnight before racking. Stout, and in fact all beers for export to a hot climate, require rather more.
For long transports the acid in powder can be simply thrown into the export casks, in which it dissolves in the course of three days instead of a week, which is required by the cold beer lying quietly.
BOTTLED BEER NOT SALICYLATED IN THE CASK.
The clean bottles must be rinsed with a solution of 1 part of salicylic acid in 4 or 5 parts of spirit (free from fusel oil), which can be poured from 1 bottle to another. Or, a small pinch of the acid in powder is placed in every bottle before filling.
The corks should always be boiled in water containing 1 ounce to the gallon, which is also efficient in disinfecting tubes, taps, etc.
CIDER.
Dissolve 3/4 of an ounce of salicylic acid in a gallon of cider, and then add this amount to each barrel of cider. This is superior to any preparation of lime. The cider must be treated when fresh.
GLUE, GELATINE, GUM ARABIC SOLUTIONS, PASTE, SIZE, STARCH, INK, SKINS OF ALL KINDS, ETC.
Are successfully preserved for a length of time from decomposition or deterioration by means of salicylic acid. One-thousandth part of the acid introduced into a vat of gelatine or into decoctions of animal matter, prevents their undergoing decomposition for an indefinite period of time. Calico printers are using half a pound of the acid to every 100 pounds of dressing starch, in order to entirely preclude the disagreeable odor arising after awhile from dry goods in store.
IN THE PROCESS OF TANNING,
If the bark-color be slightly salicylated, this liquor will not undergo the change which, instead of making the hides and skins swell, often causes the opposite effect, contracting them by an alkaline action, and at the same time imparting to them a putrid odor. Treatment with carbolic acid also leaves a most objectionable odor, especially in fine leather goods. The use of salicylic acid will thus be found highly remunerative to all tanners, as it has proved in the industries already alluded to.
IN SUGAR FACTORIES
Three drachms of salicylic acid are used to every 300 pounds of beetroot in the diffusing liquor, in order to prevent fermentation, and for destroying the parasitical growths, especially noticeable in the old material.
FOR DISINFECTING.
Fumigation with the acid purifies the air and walls of closed rooms. Simply evaporate some on a heated shovel, which must not be red-hot.
The air in crowded buildings, schools, barracks, hospitals, factories, etc., will be improved by keeping the floors sprinkled with the solution. In sick rooms this is of great importance, the dust settling on the floor being the readiest receptacle and means of transmitting the microscopic fungi or germs of infection which float in the air.
VESSELS, CORKS, ETC.,
Are very well cleaned and disinfected by washing them with an aqueous solution of the acid. This deserves especial notice.
It is evident that numerous advantageous applications of salicylic acid are carried out besides those enumerated above, but the descriptions already given will enable any person interested in the matter to find out the best means of deriving profit from the wonderful properties of this extremely useful substance.