Njv. 1, 1864.] THE TECHNOLOGIST. 



ON CHEMISTRY APPLIED TO THE ARTS. 157 



tke rapidity with which he converts hides into leather, and also to the 

 remarkable toughness which his leather possesses. To attain these 

 desirable ends, Mr. Preller proceeds as follows : — The hides are washed, 

 slightly limed, unhaired, fleshed, and partially dried ; they are then 

 smeared with a mixture made of fatty matters and rye flour, which 

 having been prepared a few days previously has entered into fermenta- 

 tion, a process which has so modified the fatty matters as to render them 

 more susceptible of immediate absorption by the hide. I think that this 

 feature of Mr. Preller's plan deserves the serious notice of all engaged in 

 the manufacture of oiled leathers, as it appears to prove that fatty acids 

 (or modified fatty matters) are better suited for combination with skins 

 than neutral fats. The hides, with additional fatty matters, are then 

 introduced into the large American drams, previously noticed in speak- 

 ing of currying. After four days they are removed, washed in an 

 alkaline fluid, worked with a pummel and slicker, and when dried are 

 ready for market. 



Gloves. — The manufacture of this article is now a most important 

 branch of trade, and is the means of giving employment to large numbers 

 of people in several towns in this country as well as on the Continent. 

 To render the above-mentioned oiled leather sufficiently soft and 

 pliable for gloves it is necessary to submit it to the following further 

 operations : — The chamois, kid, or other skins are rubbed over with a 

 solution, composed of lib. of soap dissolved in half a gallon of water, to 

 which is added l^lb. of rape-seed oil and twenty yolks of eggs, or, what 

 has been recently found to answer better than eggs, a quantity of the brains 

 of animals reduced to pulp. The use of the two latter substances is 

 extremely interesting in a scientific point of view, for they both contain 

 a peculiar nitrogenated matter called " vitalline," and specially fatty 

 matters called "oleophosphoric and phosphoglyceric acids," which, doubt- 

 less, by their peculiar composition, communicate to the skins those 

 properties which characterise this class of leather. The skins are then 

 washed and dyed in various colours, after which they are softened, and 

 rubbed with an instrument adapted to slightly raise the surface, and 

 give it that well-known velvety appearance belonging to glove skins. 



Bleaching of Skins. — The only process known until recently for 

 imperfectly bleaching chamois and glove skins was that of submitting 

 them to the fumes of sulphur in combustion, or sulphurous acid, 

 but latterly two modes of attaining that object have been proposed. 

 The first consists in dipping skins, for two days, in a weak solution of 

 neutral hypochlorite of soda, washing, drying, and rubbing them with 

 soap and oil. The second mode is to dip glove skins into a solution of 

 permanganate of potash, when they soon assume a brownish colour, 

 due to the liberation of the oxygen of the permanganate of 

 potash, and the fixation of the hydrate of sesquioxide of manganese 

 by the skin. The skins so acted on are washed and then dipped 

 in a solution of sulphurous acid, which becomes converted into 



