| Caoutchouc | 10 |
| Rectified petroleum | 120 |
| Asphalt | 20 |
To prepare this, the caoutchouc should be hung in a linen bag in a cask with a very large bung, or in a large jar, so that the bag shall be only half immersed. This is kept in a warm place for from ten to fourteen days, till the solution is effected. Then the asphaltum may be melted in an iron kettle. Let the rubber solution slowly run into the kettle over a gentle heat, and stir in the one to the other till the mass is thoroughly preserved are put in the bag; the edge is then turned incorporated. When this is effected pour the mixture into moulds which have been oiled to prevent adhesion. The result is dark brown or black thin cakes, which are broken with difficulty. The excellence of this cement is somewhat counteracted by the difficulty or care which must be observed in using it. To do this, put the vessel in which it is to be melted in another or a balneum mariæ, as for glue, filled with boiling water. When fluid take the kettle from the fire and subject it directly to heat till it attains a temperature of 150° centigrade. When it is possible, heat the object to be glued to 100°. The thinner the coat and the hotter the surface the better will it adhere, unless the objects be such as hard boards. In all cases as strong a pressure as possible should be employed to bring the two parts together, which should be continued till the glue has dried. Boxes which are cemented together by means of marine glue and are also nailed are of extraordinary strength, and may be thus made air-tight and waterproof. Those who intend to send articles which can be affected by sea-air, such as silks and tea, which change their colour and quality even when packed in the tightest ordinary cases, should employ boxes well secured with good marine glue. It is also invaluable to secure clothing against moths, for if anything be very thoroughly dusted and there are no moths in it, none can get in if it be enclosed in a box rendered air-tight.
Apropos of which I would say that in America moths, which are far more of a pest than in Europe, are effectively excluded by means of bags of strong paper, well tarpaulined or tarred. The objects to be over and warmed, so that it seals itself up. Strong paper bags are better than any trunks to exclude moths, but they must always be well gummed up. Tobacco is no protection at all against these insects. I have even had an old woollen Turkish tobacco-bag which had been in use ten years, and which was partly full of tobacco, almost devoured by moths, which must have eaten no small quantity of tobacco in so doing. Nor is camphor or any other scent half as effective as hermetic closing in some substance which insects will not eat.
Lehner gives a suggestion regarding the rendering walls air-tight which is of such remarkable practical utility that it ought to be enforced by health laws in every house. Whenever walls have any tendency to absorb dampness—and all have it in damp weather, especially in underground rooms—it is far more dangerous than is generally supposed to put paper on them. This is so much the case that where workmen, from carelessness, paste one coat of paper over another on a damp wall, the mass in time gives out a very poisonous exhalation, so that an instance is recorded in which several people died, one after the other, in consequence of sleeping in such a room. To prevent this take the following waterproof cement:—
| Caoutchouc | 10 |
| Washed chalk | 10 |
| Oil of turpentine | 20 |
| Bisulphide of carbon | 10 |
| Resin (colophonium) | 5 |
| Asphalt | 5 |
These are combined in a large flask, kept in a moderately warm place, and often shaken till well incorporated. The wall to be covered should be brushed and wiped, and in some cases heated, until extremely dry. Then, using the cement, apply the paper in the ordinary way. It will stick with great tenacity, this being a very tight and strong glue. All wall-paper whatever is more or less productive of malaria in damp weather, as is the smell of a damp library, or one where the scent of old paper is rankly and offensively perceptible. Therefore every precaution should be taken to render it innocuous.
Even if no paper be applied, this cement is very valuable when simply used to coat the interior or exterior of damp walls. It can, of course, be used to repair many articles of indiarubber, and to mend shoes, tan garments, &c. Apropos of which latter I may here remark that all persons who intend to rough it in the bush as colonists, or go into any region where mending or getting mended is difficult—as I myself have many a time experienced—would do well to carry a tight tin box of waterproof glue, with which torn shoes, and very often torn clothes, can be promptly repaired. In fact, with the aid of a little rough stitching, or even without it, garments of leather, muslin, and even of cloth can be made to hold together with certain cements, which will literally bind anything.
It is well worth while for those who propose to live in the wilderness, wherever it may be, to know how to prepare or make indiarubber garments. The recipe is very easily made:—
| Gutta-percha | 10 |
| Benzine | 100 |
| Linseed-oil varnish | 100 |
The gutta-percha is dissolved in the benzine; the solution, when clear, is poured into a bottle already containing the varnish, and all is then thoroughly shaken. This mixture, when spread on woven fabrics of any kind, renders them completely waterproof. The garments can then be cut out and “sewed;” that is, bound together with the same cement. According to Lehner, this cement can be used for making the soles of shoes, and is marvellously elastic. All travellers, and assuredly all housekeepers, should have this cement among their possessions.