Foods and Their Adulteration / Origin, Manufacture, and Composition of Food Products; Description of Common Adulterations, Food Standards, and National Food Laws and Regulations

by Harvey Washington Wiley

LARD.

The fat of swine, properly separated from the other tissues, is known as lard. The process of separation is termed “rendering.” Various methods of rendering are practiced, all depending, however, upon the use of heat, which liquefies the fat and gradually frees it from its connective tissues.

Parts of Fat Used for Lard Making.

—In the making of lard the highest grades are produced from the fat lining the back of the animal and that connected with the intestines. The sheets of fat which are found lining the back of the animal furnishes a variety known as leaf lard. All parts of the fat of the animal not used in the meats themselves may be used in the manufacture of lard. In the preparation of the carcass, the parts cut off in trimming the pieces and containing fat are sent to the rendering tank. The leaf lard is also removed by tearing it off from the back of the animal, and the intestinal fat is separated from the viscera in like manner. There is probably no question of wholesomeness between the lards made from different parts of the carcass. The lard differs in its chemical composition and its physical consistence as determined by its location in the body. Inasmuch as it is important that lard should have a certain degree of consistence even in summer time and not become too soft or liquid in character, the lard which has a high melting point is preferred, especially during the summer. The lards made from the feet and some other parts of the hog have lower melting points. The different kinds of fat from all parts of the animal might be mixed together and a lard made therefrom representing the average consistence of the fat of the whole body. A small quantity of stearin is often added to raise the melting point, but the addition of this substance without notice must be regarded as an adulteration.

Names of Different Kinds of Lard.

—The names applied to the different kinds of lard may be referred principally to the parts of fat used, such as leaf lard, intestinal lard, etc., or to the method of preparing it. The old-fashioned method of preparing lard for family use consisted in placing the fat in an open kettle and heating usually over the open fire. The rendering takes place as the mass increases in temperature, so that the residual tissues become browned by the high temperature reached. Lard made in this way is of most excellent quality and, of course, being made under family supervision, its character is well understood and the parts of the body used are well known. In the large packing establishments the lard is usually rendered by the application of heat in the form of steam under pressure, of a suitable temperature to make the character of lard uniform. Large yields can be secured in this way with less charring of the residual tissues, and consequently a finer and whiter color in the lard itself. Lard of this kind is sometimes known as steam rendered lard.

Uses of Lard.

—The fat of swine prepared as above mentioned, and known as lard, finds a very extended use in every kitchen. It is mixed with various forms of bread making materials, cake, etc., and is often known in this sense as “shortening.” It is also employed for lubricating the pans and other culinary utensils used for baking purposes. It is sometimes employed for the purpose of cooking by the process of frying or of introducing the substance to be cooked directly into the hot lard, as in the frying of oysters, the making of doughnuts, and similar operations. Lard has come to be looked upon as a necessity in every kitchen, even of the humblest citizen.

Many objections are made to the use of lard on hygienic grounds, and probably on account of its cheapness and general utility it is more freely used in American cooking than it should be. In other words, American cooking is under the reproach of being too greasy. There is no reason to question the digestive and nutritive value of lard when used in proper quantities and in proper conditions. It is a typical fat food composed of materials which are almost wholly oxidized in the body and which upon combustion produce a higher number of units of heat than that of any other class of food substances.

COMPOSITION OF DIFFERENT VARIETIES OF AMERICAN LARD.

	Specific Gravity.	Saponi- fication Equiv- alent.	Melting Point.	Melting Point of Fatty Acid.	Crystal- lizing Point of Fatty Acid.	Rise of Temper- ature with Sulfuric Acid.	Iodin Ab- sorbed.	Water.
			C.°	C.°	C.°	C.°	Percent	Percent
Leaf lard,	.9057	272.64	41.6	43.0	40.40	39.7	59.60	.165
Pure leaf lard,	.9028	281.01	44.9	42.8	40.40	37.1	53.04	.025
Prime steam lard,	.9052	279.06	38.4	41.8	39.53	33.7	63.84	.040

Adulteration of Lard.

—The principal adulteration to which lard is subjected is admixture with other and cheaper fats. Among the fats which are used for this purpose may be mentioned beef fat and cottonseed oil. Beef fat has a higher melting point than lard and cottonseed oil a much lower melting point, being liquid at ordinary temperatures. A mixture of beef fat and cottonseed oil may, therefore, be made, having approximately the same melting point as lard itself. The addition of this mixture to lard would not alter its melting point to any sensible extent. Instead of using the whole cottonseed oil for the purpose mentioned it may be previously chilled and its product of a higher melting point, or as it is sometimes called, the stearin of cottonseed oil, may be used for admixture with lard. Large quantities of these mixed fats were formerly made in this country under the name of “compound lard” in which the above adulterants were the chief constituents. The laws of the various states are happily of a character which forbids the sale of a mixture of a compound of lard and other fats under the name of lard, although there is no objection to such admixture from a hygienic and dietetic point of view. There are many hygienists who are of the opinion that the more extended use of vegetable oils instead of lard would be of value to the health of the public. If this be true, the admixture of a vegetable oil with lard would improve it from a hygienic standpoint. The principal, perhaps the sole, objection to such admixtures is their fraudulent character. Vegetable oils, especially cottonseed oil, being very much cheaper than lard, their use in lard without notification cheapens the product and defrauds the customer. Lard may also be adulterated with its own stearin. In the manufacture of lard oil a residue is left of a much higher melting point and this residue may be mixed with a vegetable oil, such as cottonseed, in the production of a compound of approximately the same melting point as lard itself. In a case of this kind both constituents are fraudulent, in as much as neither the cottonseed oil nor the lard stearin may be regarded in any sense as lard.

Detection of Adulterations.

—The presence of cottonseed oil in any form in lard is at once determined by the application of a simple color test known as the Halphen test. This is not a reliable test in those cases where the animal has been fed cottonseed.

Halphen Reaction for Cottonseed Oil.

—Carbon disulfid, containing about one percent of sulfur in solution, is mixed with an equal volume of amyl alcohol. Mix equal volumes of this reagent and the oil under examination and heat in a bath of boiling brine for fifteen minutes. In the presence of as little as one percent of cottonseed oil an orange or red color is produced, which is characteristic.

Lard and lard oil from animals fed on cottonseed meal will give a faint reaction; also the fatty acids thereof.

This test is more sensitive than the Bechi test (nitrate of silver) and less liable to give unsatisfactory results in the hands of an inexperienced person. It is not affected by rancidity. The depth of color is proportional, to a certain extent, to the amount of oil present, and by making comparative tests with cottonseed oil some idea as to the amount present can be obtained, but it must be remembered that different oils react with different intensities, and oils which have been heated from 200° to 210° C. react with greatly diminished intensity. Heating ten minutes at 250° renders cottonseed oil incapable of giving the reaction.

Cottonseed oil also has the property of reducing silver in silver nitrate to a metallic state. When mixed with a solution of silver nitrate under proper conditions a blackening or precipitation of black metallic silver is observed. This is known as the Bechi test which is conducted as follows:

Bechi or Silver Nitrate Test for Cottonseed Oil.

—Reagent: Dissolve 2 grams of silver nitrate in 200 cubic centimeters of 95 percent alcohol and 40 cubic centimeters of ether, adding one drop of nitric acid.

Mix 10 c.c. of oil or melted fat, 5 c.c. of reagent, and 10 c.c. of amyl alcohol in a test tube. Divide, heat one-half in a boiling water bath for ten minutes, and then compare with portion not heated. Any blackening due to reduced silver shows presence of cottonseed oil.

Other oils which have become rancid, and lards which have been steamed or heated at high temperature, contain decomposition products which have a reducing action on silver nitrate. There were found in testing a large number of salad oils some which contained no cottonseed oil, according to the Halphen test, but gave a brown coloration with Bechi reagent, and in some cases reduced silver. These same oils on being purified gave no reaction. Hence the oils or fats should be purified before testing.

To purify the oils and fats, heat from 20 to 30 grams on water bath for a few minutes with the addition of 25 c.c. of 95 percent alcohol, shake thoroughly, decant as much of the alcohol as possible, and wash with two percent nitric acid, and finally with water. The oil or lard thus purified will give no reduction at all if it contains no cottonseed oil. Heating the oils or fats to 100° C. or simple washing with two percent nitric acid is not sufficient, except in a few cases.

With oils the use of the Halphen and Bechi tests will be found to be useful as a means of approximately determining the amounts of adulteration present. If Halphen gives a reaction and Bechi does not, the adulteration with cottonseed oil is probably less than 10 percent.

The admixture of beef fat with lard is best detected by means of the microscope. The fat is dissolved in ether and allowed to slowly crystallize. If it is composed of pure lard the crystal assumes a form which is represented in [Fig. 8].

If, on the other hand, beef fat be mixed with lard, the crystals will assume a radiated fan-shaped appearance shown in [Fig. 9]. Even one who is an expert with the microscope may not be able without some difficulty to detect these adulterations by the simple tests above mentioned.

Fig. 8.—Lard Crystals. × 140.—(Bureau of Chemistry.)

Fig. 9.—Beef Fat Crystals. × 140.—(Bureau of Chemistry.)

Commercial Classification of Lards.

—In addition to the kinds of lard mentioned above other varieties are known in commerce.

Neutral Lard.

—This, which is one of the best varieties of lard, is made from the fat derived from the leaf lard of the slaughtered animal in a perfectly fresh state, that is, taken immediately after slaughter and before the carcass is cold. The leaf lard, when it is removed from the animal, is at once placed in cold storage or put into cold water, in order to rapidly remove the animal heat. As soon as it is thoroughly chilled it is reduced to a pulp in a grinder and sent at once to the rendering kettle. The fat is rendered at a very low temperature, from 105 to 120 degrees F. (40-50 degrees C). It is evident that only a part of the lard is separated at this temperature, and this part is regarded as being of the best quality, almost tasteless, free of acids and other impurities. The residue from the making of neutral lard is sent to other kettles, where it is subjected to a higher temperature and the remainder of the lard extracted, which is sold under the name of another grade. Neutral lard, obtained as above, while still liquid, is washed with water containing a trace of sodium carbonate, common salt, or a dilute acid. The product thus formed is almost neutral in its reaction to litmus paper containing not to exceed .25 percent of free acid, but it has more water and mineral matter than is found in the pure rendered untreated lard. The neutral lard made in this way is not used so commonly for culinary purposes but chiefly in the manufacture of oleomargarine.

Leaf Lard.

—The residue of lard obtained by rendering the unseparated part of lard from the above process at a higher temperature is also of a high quality and is sometimes improperly designated leaf lard, a term which should be reserved for the whole product instead of a part obtained by rendering the residual leaf fat.

Choice Kettle-rendered Lard.

—The amount of neutral lard which is demanded in the manufacture of oleomargarine does not by any means exhaust the supply of leaf lard. For making choice kettle-rendered lard the leaf lard together with the fat cut from the back of the animal is rendered in steam-jacketed open kettles and produces a lard of a high quality known as kettle-rendered or choice kettle-rendered lard. The hide is removed from the fat portion of the back used for this purpose before the rendering. Both the leaf and pieces of the back are passed through a fine sausage grinder before they enter the rendering kettle. According to the requirements of the Chicago Board of Trade, choice lard, which is another term for the above variety, is to be made from leaf and trimmings only, either steam-rendered or kettle-rendered, and the manner of rendering to be branded on each package.

Prime Steam Lard.

—The prime steam lard of commerce is made as follows: The whole head of the hog, after the removal of the jowl, is used for rendering. The heads are placed in the bottom of the rendering tank. The mesenteric fat adhering to the small intestines is also used in the tank. Any fat that may be attached to the heart or other organs of the animal may also be used. In those factories where kettle-rendered lard is not made the scrap fat from the back of the animals and trimmings are also used. When there is an excess of leaf it is also put in the rendering tank and, in general, all the fat portions of the body which are removed in the trimming process. It is thus seen that prime steam lard is a term which may practically represent the average fat of the whole animal.

Prime steam lard is thus defined by the Chicago Board of Trade: “Standard prime steam lard shall be solely the product of the trimmings and other fat parts of hogs, rendered in tanks by the direct application of steam, and without subsequent change in grain or character by the use of agitators or other machinery except as such change may unavoidably come from transportation. It shall have proper color, flavor, and soundness for keeping, and no material which has been salted shall be included. The name and location of the renderer and the grade of the lard shall be plainly branded on each package at the time of packing.” All the lard which is made is subjected to the approval of inspectors both as to the material employed and the method of procedure, together with the character of the final product.

Disposition of the Intestines of the Hog.

—In the term intestines is included all of the abdominal viscera of the animal but not the thoracic viscera, namely, the heart and lungs. The material is handled in the following way: When the animal is opened the viscera are separated, including the flesh surrounding the anus and a strip containing the external genito-urinary organs. The heart is thrown to one side and the fatty portions trimmed off for lard. The rest of the heart is used for sausage or for fertilizer. The lungs and liver are either used in the manufacture of sausage or for fertilizer. The rectum and large intestines are separated from the intestinal fat and peritoneum and, along with the adhering flesh and genito-urinary organs, sent to the trimmer. All flesh from the above-mentioned organs is cut away and the intestine proper is used for sausage casings. The trimmings, including the genito-urinary organs, are washed and placed in the rendering tank where lard is made. The small intestine is also separated from the fatty membrane surrounding it and prepared for sausage casings. The remaining material, consisting of the peritoneum, diaphragm, stomach, and adhering membranes, together with the intestinal fat, constitutes the “guts” which are subjected to washing in three or four different tanks. In the first tank the stomach and peritoneum are split open, and also any portion of the intestines which still adhere to the peritoneum. The portions then go from tank to tank, usually four in number, and are then ready for the rendering tank. The omentum fat is cut from the kidneys, and the kidneys with any adhering fat go into the rendering vat. The spleen, pancreas, vocal cords, trachea, and œsophagus also go into the tank.

In general it may be said that everything connected with the viscera go into the rendering tank with the following exceptions: First, that portion of the intestines which is saved for sausage casings; second, the liver and lungs; third, that part of the heart free from fat.

In the killing of small hogs, where the intestines are not of sufficient size to be suitable for sausage casings, they also go into the rendering tank. It should be stated here that the grease or lard obtained by the rendering of the above described viscera, according to the statements of the manufacturers, is used solely in the manufacture of lard oil and soap, and does not enter into the lard of commerce.

When the processes of manufacture are properly controlled by official inspection the public may be assured that this disposition of the fat obtained by the rendering of the intestinal viscera is secured.

Butchers’ Lard.

—A considerable quantity of lard is made for commercial purposes by the small butcher for family use, etc. This lard is made almost exclusively by rendering in the open kettle. In the country where butchering is conducted for family use the ordinary open kettle is placed over an open fire. All parts of the fat of the animal which can be easily separated and the scraps derived from trimming the animal are used for rendering. The offal and refuse of the animal are also rendered separately and the product used for soap grease. The lard made in this way is regarded as perfectly wholesome, but it is frequently dark-colored from the charring due to rendering over the open fire and by reason of using some portions of the animal, such as tendons, from which glue is made. Such lard may contain traces or even considerable quantities of glue which, however, cannot be regarded as an unwholesome product. The partially browned residues in the kettle in the country are known as “cracklings” and are used for soap grease.

Inedible Hog Fat Products.

—In the shipping of hogs a great many are smothered and others die of disease or are in a condition, at the time of slaughter, which renders them unfit for human food, either by the presence of disease or otherwise. The fats are separated from dead animals of this class and are used for technical purposes such as burning oils, soap grease, etc. There are several varieties of these inedible fats of which the following are the principal:

White Grease.

—This grease is made chiefly from hogs which die in transit by being smothered or from freezing. Formerly it was the custom to make white grease also from the animals which died of disease, but the manufacture of this product has been restricted by certain state laws which forbid the use of animals which die of particular diseases, such as hog cholera, from being used for any purpose whatever and their carcasses are to be buried so as to remove all danger of infection.

Brown Grease.

—Brown grease is a product of a lower grade than white grease and is made usually by rendering the whole animal. It is one of the by-products in the manufacture of tankage from condemned animal carcasses, the tankage being used as fertilizer. Both white and brown grease are used chiefly in the manufacture of low grade lard oil and in the making of soap.

Yellow Grease.

—Yellow grease is a product intermediate in value between white and brown grease. It is made chiefly from the carcasses of animals that die while on the packers’ hands. It is used for the same purpose as white and brown grease.

Pig’s-foot Grease.

—A special variety of grease is made from pigs’ feet as a by-product in the glue factory. This grease is used also in making lard oil and soap. It is evident that these varieties of grease are only inedible varieties of lard, and through proper inspection the public is protected against the use of these varieties of grease in the edible product.

Lard Stearin.

—Mention has already been made of the fact that by melting a fat and cooling it slowly towards its solidifying point, certain constituents of the fat which have a higher melting point separate first, leaving those constituents with a lower melting point still in a liquid condition. Those portions of an oil or fat which separate first under such conditions, are the constituents of the product which is known as stearin, while the part that remains liquid is the constituent known as olein. Lard stearin is made principally for the manufacture of mixtures and is a by-product of the highest grade of lard oil. Lard stearin is made as follows: The lard is melted and kept in a crystallizing room at from 50 to 60 degrees F., until it is filled with the crystals of the separated stearin. The product is then wrapped in the form of cakes with cloth. Each package contains from 10 to 20 pounds. The cakes are then placed in a large press with suitable arrangements to facilitate the escape of the oil and maintain the low temperature. The pressure is applied very gradually at first, and as the process advances, with increasing power. The high grade oil obtained in this way is known as prime or extra lard oil and is used for illuminating and lubricating purposes. The resulting solid product, which is principally stearin, is used as one of the adulterants of lard, that is, in making a mixture which is sometimes called lard, composed of lard stearin and cottonseed oil.

Fig. 10.

Tanks Used for Producing Lard Under Pressure.

—There are various forms of tanks used for producing steam rendered lard. In the open kettle there is a jacketed arrangement by means of which steam, at the proper temperature, is made to act upon the contents of the inner kettle. In the closed kettle the steam may be applied in the form of a jacketed arrangement or introduced directly into the kettle. The residues which remain after the steaming is completed and after the lard has been drawn off are withdrawn from the conical lower portion of the kettle which can be opened for the removal of these residues. A typical kettle for rendering lard is shown in [Fig. 10]. The fragments of meat to be received are placed in the opening M which is then properly closed when the tank is full. Steam is admitted and the condensation which is produced at first by the cold contents of the tank is drawn off through a water pipe. After the tank is thoroughly heated and the fat begins to separate the lard will rise above the water and the solid fragments and at the end of the process will fill the upper part of the tank. By means of the cocks at D it can be determined to what depth the tank is filled with lard and the lard can be drawn off through these cocks until water begins to flow. The bottom of the tank at G is then opened and the residues withdrawn, dried and ground for tankage.

Physical Properties of Lard.—Specific Gravity.—

The specific gravity of pure lard is to be determined at some definite temperature, inasmuch as a statement of its specific gravity without some reference to the temperature at which it is determined is likely to be misleading. It is not convenient to ascertain the specific gravity of a lard at a temperature below its melting point. It is customary, therefore, either to take the specific gravity at about 40 degrees C., or at a temperature of boiling water.

The average specific gravity of pure lard at 40 degrees C. (104 degrees F.), regarding water as 100, is 89, and at 100 degrees C. it is 86, the weight of water being determined at the point of greatest density, namely, 4 degrees C. (39 degrees F.). Unfortunately the specific gravity of pure lard is not very greatly different from that of other oils or other fats used in its adulteration. For this reason it is not of the highest value for determining whether or not the pure article has been subjected to adulteration.

Melting Point.

—The melting point of a pure lard is a physical characteristic of great value, since it is chiefly influenced by the part of the body of the animal from which it is made. The fat which is rendered from the foot of the hog has the lowest melting point, namely, about 35 degrees C. (95° F.). The fat adhering to the intestines has the highest melting point, namely, 44 degrees C. (111 degrees F.). The fat derived from the head of the hog has a slightly higher melting point than that from the feet. The kidney fat has a melting point of 42.5 degrees C. (108.2 degrees F.). In the steam rendered lards, representing the average of lards passed upon by the Chicago Board of Trade, the average melting point is found to be about 37 degrees C. (98.7 degrees F.). The melting point of superior or leaf lard has an average value of about 40 degrees C. (104 degrees F.).

Color Reaction.

—A pure high grade lard when mixed on a white porcelain plate with the proper amount of sulfuric or nitric acid should give only a very slight coloration. The production of any considerable quantity of color, either brown or black, indicates the presence of organic impurities in the lard.

Rise of Temperature with Sulfuric Acid.

—The various fats give different degrees of heat when mixed, under certain conditions, with strong sulfuric acid. It is possible to determine the approximate degree of the adulteration of lard by applying this test. The operation is a simple one and is conducted in the apparatus shown in [Fig. 11]. A common test tube about 24 cubic centimeters in length and 5 cubic centimeters in diameter is hung as indicated in the figure, provided with a stopper carrying a thermometer in the center with a bent glass rod stirrer passed loosely through the stopper on the side and a funnel for the introduction of the acid on another side of the thermometer. A coil which is on the stirring rod is so arranged as to permit the bulb of the thermometer to pass through its center.

Fig. 11.

Manipulation.

—Fifty cubic centimeters of the fat or oil to be examined are placed in the test tube and warmed or cooled, as the case may be, until the temperature is the one required for the beginning of the experiment, say 35 degrees C.; 10 cubic centimeters of the strongest sulfuric acid at the same temperature are placed in the funnel, the stopper being firmly fixed in its place; the test tube containing the oil is placed in a non-conducting receptacle; the wooden cylinder lined with cork, used in sending glass bottles by mail, is found to be convenient for this purpose. The glass rod or stirrer which fits loosely in the stopper, so as to be moved rapidly up and down, is held by the right hand of the operator; with his left hand he opens the glass stop-cock of the funnel and allows the sulfuric acid to flow in upon the oil. The glass stirring rod is now moved rapidly up and down, for about 20 seconds, thus securing a thorough mixture of the oil and acid. The mercury rises rapidly in the thermometer and after two or three minutes reaches a maximum, and then, after two or three minutes more, begins to descend. The reading is made at the maximum point reached by the mercury. With pure cottonseed oil, linseed oil and some other substances the rise of temperature is so great as to produce ebullition in the mass, causing it to foam up and fill the tube. To avoid this, smaller quantities of acid should be used or the oil in question be diluted with a less thermogenic one, so that the maximum temperature may not be high enough to produce the effect cited.

Chemical Properties.—Volatile Acids.

—The quantity of volatile acid arising on the decomposition of a soap made by the saponification of lard is very minute in lard of high quality. The total amount of volatile acid should not be in excess of that necessary to saturate .2 cubic centimeter of deci-normal alkali solution.

Fixed Acid.

—The quantity of fixed acid, consisting principally of oleic and stearic, in pure lard should not be less than 93 percent. The total quantity of free acid in lard, that is, acid uncombined with the glycerine, should not exceed one-half of one percent, and in neutral lard should be much less than this.

Quantity of Iodin Absorbed.

—All common fats and oils have the property of absorbing, under given conditions, certain quantities of iodin. Lard of the highest quality should not absorb more than 60 percent of its weight of iodin. The lard made from the feet and certain other parts of the animal, however, may have a larger iodin number, rising as high as 75 or even 80.

Properties of Lard.

—The average properties of different classes of lard in relation to physical and optical conditions are shown in the following table:

Specific Gravity. 35° C.	Melting Point. ° C.	Refractive Index. 25° C.	Rise of Temperature with Sulfuric Acid. ° C.	Water. Percent.	Iodin Absorbed. Percent.
.9053	40.7	1.4620	41.5	.077	62.48

The above table is the average composition of nineteen samples of lard furnished under affidavits of purity and which appear from their chemical and physical properties to be composed purely of the fat of swine taken from those parts of the animal usually devoted to lard making. The average data may be regarded as representing the properties of the ordinary pure commercial lard on the market.

Average Properties of Steam Lard.

—Below is given the average composition of eleven samples of steam lard furnished under affidavit and, apparently, as judged by their chemical and physical properties, composed solely of the fat of swine. Steam lards are not of as high a quality as the lards contained in the preceding table. They have usually a distinctively strong odor, quite different from that of lards which are rendered in open kettles at low temperature and from selected portions of fat.

Specific Gravity. 35° C.	Melting Point. ° C.	Refractive Index. 25° C.	Rise of Temperature with Sulfuric Acid. ° C.	Water. Percent.	Iodin Absorbed. Percent.
.9055	37.0	1.4623	39.9	.109	62.86

Properties of Adulterated Lards.

—It is possible to mix together the different materials used in making adulterated lard in such a manner as to produce a compound which in some respects resembles the natural product. This compound, however, necessarily differs from the natural product in its physical and microscopic properties and in its reaction with various chemicals which give distinct color with the different fats and oils used as adulterants. The mean properties of thirteen samples of mixed or compound lards are shown in the following table:

Specific Gravity. 35° C.	Melting Point. ° C.	Refractive Index. 25° C.	Rise of Temperature with Sulfuric Acid. ° C.	Water. Percent.	Iodin. Percent.
.9060	40.6	1.4634	46.5	.098	63.58

These lards, in addition to the above properties, show distinct color reaction with sulfuric and nitric acid and with the reagents which are distinctive of cottonseed oil. They are mostly mixtures of lard and tallow stearin with cotton oil or cotton oil stearin.

In addition to the adulterations already mentioned as mixing with cottonseed oil may be added the use of coconut oil. It is not probable that in the United States any adulteration of lard with coconut oil has been made for commercial purposes. Such an adulteration, however, is practiced in some foreign countries. Coconut oil contains considerable quantities of volatile acid, and, therefore, when used as an adulterant of lard, would increase the normal quantity of volatile acid materially. One sample examined by Allen, of England, was found to contain a quantity of coconut oil, amounting to 33 percent.

Summary.

—In the preceding pages has been given a description of the character of lard, the sources from which it is made, the method of its preparation, its chemical and physical properties and the common adulterations to which it is subjected. There is no question of the wholesomeness of the usual fats and oils, or parts thereof, which are used in the sophistication of lards. The adulteration is intended solely for fraudulent purposes, that is, to sell under the name of a higher priced article one of a lower price.

There are many persons who prefer to use vegetable oils and fats as substitutes for lard in all cases. It is only fair to the consumer that the character of a fat and oil, however, for edible purposes be plainly made known to the purchaser. He is then to judge of the propriety or impropriety of using the articles in question. It seems quite certain that the use of vegetable oils and fats will be greatly increased in this country. All hygienists grant that they are at least equally as wholesome as the animal fat and oil. They are certainly less open to suspicion as having been derived from diseased sources. As a rule, they are carefully expressed and properly refined, free from rancidity and from any mechanical or chemical constituents which render them unpalatable or unwholesome. They are generally much cheaper, perhaps the only exception being that of olive oil. These vegetable oils, as a rule, are excellent for salad dressing, for frying and general cooking purposes and for the ordinary uses to which lard and other animal fats are devoted. A proper labeling of all such packages would increase the quantity consumed, restoring confidence to the public in the character of the goods purchased, and prove of mutual benefit to the grower, the manufacturer and the consumer. It must be remembered, however, that there are many people who prefer the animal fats, and so there will probably always be a large field for their use. Such consumers are entitled to secure the pure article, properly prepared from healthy animals and free from rancidity and organic impurities. Lard and other animal fats offered in this way will have a greater vogue, command a greater degree of confidence and secure a larger trade than if sold under conditions engendering suspicion and distrust.