It may also happen to a traveller to find himself with an aching hollow tooth in a region where no dentist is accessible. Should he have with him some gutta-percha (bleached is best for this purpose) he may combine it with very finely pulverised glass. (To levigate or powder anything as fine as flour, it must be pounded in a mortar, or on metal or hard stone under water.) Then warm and thoroughly mix the gutta-percha and glass. Make it into little pencils, which, when they are to be used, must be dipped in hot water. This cement may be also used for a great variety of other purposes.
A very admirable cement, which should be found in every stable and known to every one who owns a horse, is made as follows:—
| Hartshorn and resin ammoniacum (Ammoniakharz) | 10 |
| Purified gutta-percha | 20-25 |
Heat the gutta-percha to 90°-100° centigrade, and thoroughly incorporate it with the powdered resin. The chief use of this admirable composition is to fill up cracks or splits in horses’ hoofs. It may also be used for plaster on occasion. To apply it to hoofs, warm it and spread it in with a warmed knife. It sets so hard that it will hold nails.
In mending or making, it may be observed that a very little indiarubber or gutta-percha may be combined with benzole or ether, or rectified petroleum in large amount, which soon becomes dense. Therefore, to produce a surface or a skin, we first spread a thin coat over the object or mould, and then apply another with a broad, soft brush or “dabber” with great care, so as to make it of uniform thickness. It is, therefore, best to have the preparation always rather thin, and use it at the right time, and not when it has become dense by long keeping. In the latter case add more of the solvent.
Glass bottles or vials containing liquids are often broken, even by the pressure of soft objects, such as clothing, when placed in trunks. It is therefore advisable to dip or coat them with this solution, which forms a bag which will contain the fluid; that is, unless it be of a nature which will soften it. I have known a bottle of hair-oil to be packed in a valuable cashmere shawl, which was almost ruined by its breaking, and which could have easily been prevented by this easy precaution.
Any apothecary will make up these recipes.
A very curious and valuable imitation of indiarubber waterproof cloth is made as follows:—Caseine is macerated with water and with borax to a solution. The cloth is dipped in this, and when quite dry, again dipped into a strong infusion of gall-apples. This is a kind of tanning.
For exhaustive information on the subject of indiarubber the technologist may consult Kautschuk und Guttapercha, by Raimund Hoffer, Leipzig, 1892, which is, I believe, the latest and best work on this important subject.