1835.] Analysis of Raw Silk. 711 



tion has ceased, the solution lets fall, by spontaneous evaporation, a 

 few filamentous bunches of a white colour, and apparently fatty nature ; 

 but in quantity too small for more particular examination. 



B. The flocculent precipitate above mentioned, being collected 

 and dried, weighed 0*1. It had the consistency, fusibility, and other 

 sensible properties of wax. 



C. The silk, still perfectly elastic, was now transferred to a deep 

 silver vessel, and boiled with successive portions of distilled water as 

 long as any sensible action was produced. A colourless, opalescent 

 solution was obtained. It was frothy and viscid j and exhibited 

 scarce any tendency to deposit the particles it held in suspension. A 

 solution of bi-chloride of mercury, cautiously dropped from a gradua- 

 ted tube, threw down a bulky coagulum, which after boiling, became 

 much condensed, and permitted the easy decantation of the clear 

 fluid. This precipitate, well washed and dried, weighed (deducting 

 1*4 grains, the amount of metallic salt employed), 8'9 grains. It had 

 all the well known characteristics of albumen. 



D. The clear fluid decanted in process C. being evaporated to 

 dryness in a steam bath, left a nearly colourless, transparent, brittle 

 mass, resembling gum. It weighed 13*0 grains, and had a tendency 

 to soften, from the presence of a small quantity of deliquescent salts. 

 It dissolved readily in water, from which neither the bi-chloride 

 nor tan threw it down. It exhibited no tendency to gelatinize, 

 however concentrated; and was copiously precipitated by sub-acetate 

 of lead. 



E. Alcohol now took but a feeble tinge from the silk, which still 

 retained a little harshness. A very dilute solution of caustic potash 

 was accordingly exhibited ; and after a few hours digestion, was 

 poured off", exactly neutralized with muriatic acid, and treated with 

 the bi-chloride as in process C. The precipitate of albumen thus 

 obtained weighed - 4 grains. 



F. Finally, the silky fibre, which had now attained its full lustre 

 and flexibility, weighed 765 ; exhibiting a loss of 06 upon the total, 

 attributable to hygrometric moisture ; the whole of the products 

 being dried at a steam heat immediately before weighment. The 

 following are the results of the analysis : 



A. Resinous colouring matter, and white filamentous substance # 9 



B. Wax, 01 



C. and E. Albumen, 8*9 



D. Mucus, 13-0 



F. Bleached fibre, 76-5 



F. Hygrometric moisture 0*6 



Grains, 100.0 



4 y 2 



