SILK. 341 



of each remained. On cooling both deposited bulky flocks, 

 which were separated by the filter. The liquid being still far- 

 ther concentrated deposited more flocks, which were added to the 

 former ones. These flocks from the yellow silk amounted to 

 1 -03 grammes, and from the white to 0-62, or 1*33 per cent, fro 

 the yellow, and 1-04 from the white. 



3. When the alcoholic tincture ceased to deposit any more 

 flocks it was evaporated to dryness. That from the white silk 

 gave out a peculiar smell and let fall a colouring matter, which 

 adhered to the bottom of the vessel in stripes. The alcohol from 

 the yellow silk deposited a similar substance of a yellow colour. 



This matter from the yellow weighed Oil grammes, and from 

 the white 0*15 gramme. Or that from the yellow silk was 0*14 

 per cent., and that from the white 0-25 per cent. The residue 

 from the white silk had a fine red colour. 



4. The silks were now digested in repeated portions of ether, 

 till that liquid ceased to dissolve anything. The ether being eva- 

 porated, there remained a colourless residuum, weighing from 

 the yellow silk 0-01 gramme, and from the white 0-03 ; or 0*012 

 per cent, from the yellow, and 0-05 from the white. 



After these processes, the yellow and white silk could not be 

 distinguished from each other by their appearance. 



5. The silk thus treated with water, alcohol, and ether was 

 now digested in concentrated acetic acid. There remained un- 

 dissolved of the yellow silk 41-19 grammes, of the white silk 

 32-18 ; or of the yellow 53*3 per cent., and of the white 54-0 

 per cent. 



6. The substance (No. 1,) which had been separated from the 

 silks by boiling them in water was treated with alcohol raised to 

 the boiling temperature. When the tinctures cooled, flocks si- 

 milar to those of (No. 2) separated. While under the liquid, 

 they were very bulky, but when the alcohol was distilled off they 

 lost much of their bulk, and formed a clammy substance very 

 small in quantity ; since that from the yellow silk weighed only 

 0-05 grammes, and that from the white 0-04 ; or that from the 

 yellow 'amounted to 0-064 per cent., and that from the white to 

 0-067 per cent. The residual alcohol being evaporated, left a 

 residue too small to be weighed. 



7. This clammy substance was digested in ether. But the 

 ether being evaporated, left a residue too small to be weighed. 



