WEIGHTING OF LEATHER. 9 



part of the body and along the back is closer fibcred than that from 

 the lower part, under the body; it becomes more open textured and 

 consequently more porous as it passes from the backbone to the 

 under side of the body. The skin over the posterior portion of the 

 body is of closer texture than that over the forequarters; conse- 

 quently the best leather is made from the hide in the region of the 

 kidneys and hips, provided the skin is sound and not damaged in 

 tanning. The leather from the " flanks" and " bellies" is more 

 porous, lighter, and more flexible than that made from the "back," 

 and in cutting the side of leather into soles the lighter and more 

 flabby the lower portions the more of it is rejected. If, however, 

 this lower portion has been stiffened and weighted with foreign 

 material, no matter how useless it is nor how soon it may wash out, 

 some shoe manufacturers will cut it into soles, thus obtaining more 

 soles from a side. Because of these facts the shoe manufacturers cal- 

 culate that weighted leather costs them less for each pair of soles than 

 the unweighted leather. 



Unloaded flabby leather makes poor shoe soles, and loading with 

 materials readily soluble in water, as glucose and Epsom salts, in- 

 creases the cost to the purchaser, and does not make soles more 

 serviceable. . 



WEIGHTING MATERIALS AND THEIR EFFECTS. 



Loading or weighting materials are cheap. Those in most general 

 use in this country are glucose, selling at 2 cents a pound; Epsom 

 salts, or magnesium sulphate, selling at 1 cent a pound; and solutions 

 of tanning or other organic materials, selling at 0.75 to 2 cents a pound. 

 Barium sulphate and lead sulphate generally formed by drumming 

 the leather first in a solution of barium chlorid, costing 2 cents a 

 pound, or of sugar of lead at 9 cents a pound, and then in sulphuric 

 acid and sodium sulphate, costing 1 cent a pound, are also employed 

 to a small extent. Of these loading materials, glucose, soluble 

 organic materials containing little or no tannin, magnesium sulphate, 

 barium sulphate, lead sulphate, and sodium sulphate are much more 

 objectionable than a small excess of actual tanning material. 



Loading with glucose, Epsom salts, barium sulphate, lead sulphate, 

 excessive quantities of tanning materials, or with water-soluble 

 organic material is often detrimental to leather. It is made hard, 

 brittle, more likely to crack, and after the loading washes out, as 

 usually happens quite readily except in the case of barium and lead 

 sulphates, it is more easily penetrated by water. Loaded leathers are 

 more expensive, less durable, and a menace to health. A distinction 

 should possibly be made between the effects of an excess of true 

 tannin and of other uncombined or loading materials. The excess of 

 true tannin may not itself be so objectionable and may even be of 

 70416 Bull. 16513 2 



