PROCEEDINGS OF THE POLYTECHNIC ASSOCIATION. 367 



TIio materials used in tlio inaiuifacturc of these h:\nd-coverings uro 

 leatlief, silk, cotton, wool, i'nv and India-rubber. The first step to be con- 

 eidered is 



THE PREPARATION OF SKINS. 



Skins for the glover's use arc prepared b}' compounds quite diDTerent from 

 those employed in the ordinary' process of tanning*. In the place of tannic 

 acid a niixttire of alum and common salt is substituted, and the skins thus 

 prepared are said to be tawed. The old process for removing the hair from 

 the .skin, previous to tawing, was to use a solution of lime — by some manu- 

 facturers the sulphide of arsenic was added to the solution; but as the 

 use of this j)oisonous compound, commonly known as orpiment, was only 

 to form the sulphide of calcium, to which the rapid_ unhairing is due, the 

 following substitute has been proposed, viz : three parts of sulphide of 

 sodium, ten parts of slacked lime and ten parts of starch. The sulphide 

 of lime may be used in place of the sodium com|)ound. To remove any 

 lime remaining on the skijis after being subjected to this process, they are 

 placed in a bran bath or in a weak solution of snl[jhnric acid, after which 

 they are ready for the alnm and salt solution. According to Berzelius, the 

 chloride of alumnium, resulting from this solution, is the preservative 

 agent. A similar solution, containing also rye flour and cgga, is subse- 

 quenlly used for a few hours, after which the skins are removed and dried. 

 They arc softened by means of an iron tool and whitened by rubbing them, 

 while stretched on a frame, with pumice stone. 



There is another process to which the Chamoise skin may be subjected 

 for the purpose of preventing putrefaction. After the skins have been 

 properly fulled the}' are placed on a table and covered with an animal oil — 

 generally sperm — rolled together and again subjected to the action of the 

 falling mill. The whole process is again repeated, after which the skins 

 are hung in a moderately heated room, when a slight fermentation takes 

 place, and the organic matter, thus modified, unites more readily with tl'.e 

 oil, and forms a permanent combination. It has been proposed to modify 

 this process by mixing r^'o tlour with the fatty matter which, after under- 

 going slight fermentation, seems to unite more readil}' with the gelatin 

 than neutral fats. 



To render this leather soft and' fit for the glove-maker it is rubbed with a 

 solution of soap and water, rape-seed oil and eggs, A pulp made of 

 animals' branis may be advantageously substituted for the eggs. This 

 wash imparts to the leather the peculiar properties belonging to this class 

 alone. When dried it is subjected to the coloring process. The common 

 process for bleaching skins for the glover's use was, until recently, to sub- 

 mit them to the fumes of burning sulphur. The object is more completely 

 accomplished by placing them for two days in a weak solution of neutral 

 hypochlorite of soda; after being cleaned and dr^'ed, a wash of soap and 

 oil is again applied. 



Another method is to dip the skins into a solution of permanganate of pot- 

 ash; after being washed they are placed in a solution of sulphurous acid 

 — sulphuric acid is formed, which unites with the oxide of manganese 

 remaining in the skin, forming a soluble compound readily removed. 



The goat and kid skins used for gloves are imported from South Ameri ca 



