BUREAU OF CHEMISTRY. 349 



TANNING AND LEATHER. 



The production of leather is of more interest to agriculture than to 

 any other industry, for not only does agriculture produce the raw 

 products of leather, the hides and the tanning materials, but it is by 

 far the largest consumer of the finished product. The chemistry and 

 the technology of leather making are therefore directly related to 

 j^rofitable agriculture. 



The results of experiments to determine the relative wearing 

 qualities of shoes made from different kinds of leather tanned by 

 various processes are given in Department Bulletin 1168, Wearing 

 Qualities of Shoe Leathers. The outstanding indications from this 

 investigation are: (i) The superior pliability of retanned chrome 

 and chrome-tanned upper leathers; {2) the features that are ob- 

 jectionable in fiber soles and the long wear of those that did not 

 develop such features; (3) the greater serviceability of rolled vege- 

 table-tanned sole leathers, as compared with unrolled leather of the 

 same thickness; (4) the strikingly longer wear of chrome-tanned sole 

 leathers, especially of the unwaxed chrome-tanned leather. 



In addition to the wear data, extensive analytical data showing 

 the composition of the original leathers and of parts of the worn 

 soles from these leathers are reported. These data involved more 

 than 1,500 determinations. The data obtained in this investigation 

 will be of value to buyers of shoes, especially to the large buyers 

 like the War Department, by indicating specifications for the most 

 suitable shoes, to manufacturers by indicating the most efficient 

 leather for making longer wearing shoes, and to tanners in aiding 

 them to improve processes for making more durable leather. 



Experiments were conducted to reduce deterioration in bookbind- 

 ing leathers. Much of the bookbinding leather used to-day is of 

 inferior quality. Attention was also given to bookbinding cloth to 

 prevent rapid fading and destruction by roaches. Fading is a 

 matter of some importance in binding yearly volumes which should 

 match in color from year to year. Attempts were made to devise a 

 roach-repellent treatment which might be applied at the bindery. 



Detailed directions for making bark-tanned sole and harness 

 leather, chrome-tanned leather, and alum-tanned lace leather on a 

 small scale are given in Farmers' Bulletin 1334, Home Tanning of 

 Leather and Small Fur Skins. 



Investigations on raw materials for leather manufacture were 

 continued. Attention was also given to the recovery and utilization 

 of tannery and leather wastes. 



WATERPROOFING, MILDEWPBOOFING, AND FIKEPEOOFING FARM FABRICS. 



The waterproofing, mildewproofing, and fireproofing of fabrics 

 for farm and other uses are of importance because of the growing 

 use of canvas as a protection against the weather. The introduction 

 of long-distance hauling by truck has greatly increased the need for 

 durable, water-resisting covers. Great quantities are used for wagon 

 covers and for the protection of grain and hay in the cock or 

 stack. Contractors and builders need dependable canvas to pro- 

 tect machinery and materials. The Army and Navy need a great 

 deal of canvas, and the summer camper is a large consumer. Often 



