UTILIZATION OF THE SKINS OF AQUATIC ANIMALS. 849 



lime solution. Alum and bark tannings are generally used, sometimes 

 both together and at others tirst the alum and then the bark liquors. 

 The method of tanning the skin shown in pi. 35 was as follows: This 

 variety of skins is very oily, and half a gill of oil may be removed 

 from the cavit}^ beneath each of several of the ])osses. The skin was 

 soaked in lukewarm water for 2i da3^s, and then beamed to remove all 

 grease, surplus flesh, and the like. It was then immersed in a solution 

 of 1 pound of alum and 4 ounces of salt to 1 gallon of water, where it 

 remained about four days; then retanned in oak liquors, the strength 

 of the liquor being increased daily. On removal from the tan liquor 

 the skin was dried without any special finishing. 



BEAVER-TAIL SKINS. 



A ver}^ characteristic leather seen occasionally in the markets is 

 made from the skin of beaver tails. This is one of the most curiously 

 marked of all of the aquatic leathers, being entirely covered with 

 unimbricated scale-like bosses of irregular outline, usually hexagonal, 

 a few pentagonal, and some quadrangular, the sides in all cases being 

 slightl}^ curved. Each of the bosses is about a third of an inch or 

 less in length. The tail itself is about 10 inches long and 4 or 5 

 inches wide, and the skin produces a piece of leather about 8 inches 

 square. Probabl}^ not over 50 pieces of this leather go on the market 

 in the course of a year, but it might readil}^ be increased to 20,000 or 

 more. It is not especially durable and is used mainly for covering 

 small jewelry boxes and the like. 



For the preparation of this leather the skin is removed by cutting 

 an incision along the middle of the under side from the base to the 

 end, and stripping it ofl^ in one piece. Sometimes this is done by the 

 trappers, but more frequently the entire tails, preserved in salt, are 

 received at the tanneries. The skin is cleared out b}" soaking in tepid 

 water for a length "of time ranging from two to eight days, according 

 to its condition, and is then limed for two or three days. It is shaved 

 on the flesh side and submitted to a japonica, sumac, or alum tanning 

 solution for about two weeks, shaved again, and cleaned with a sumac 

 or sulphuric acid solution, and then colored if desired. 



Very tough and durable leather may be made from the skin covering 

 the body of the beaver. Before the adoption of the present method 

 of cutting hatters' furs the tanneries received many of the skins from 

 which the fur had been clipped, and beaver leather was comparatively 

 common in the markets. Among the Huron Indians, whose wants 

 were largely supplied by the beaver, the skin was much used for belts, 

 bags, thongs, and even tent coverings. At present, however, leather 

 made from beaver skin is comparativel}^ unknown, many dealers in 

 fancy leathers never having seen an}". The grain is noticeable, but 

 not especially attractive, no more than that of pig skin. 



