359 Experiments and Observations on Feathers, 



Lixivium of carbonate of potash extracts a great part of 

 the colouring matter, but does not form so complete a so- 

 lution of the entire substance of lac, as when pure potash 

 is employed. 



The above alkaline solutions, by repose, afford the waxen 

 boap which has been mentioned ; and acids, being added to 

 these solutions, and to that formed by borax, precipitate 

 the lac in a flocculent state, and of a yellow or buff colour, 

 which precipitate, when melted, becomes similar to the lac 

 originally employed. If however an alkaline solution of 

 shell lac (prepared, for instance, with soda) be gradually 

 dropped into a sufficient quantity of muriatic acid diluted 

 with an equal portion of water, and nearly heated to the 

 boiling point, and if after boiling the whole for about one 

 hour the coagulum be separated, and the clear liquor be 

 carefully saturated with soda, and again made to boil, a 

 small quantity of a flocculent precipitate is oblained, which 

 was found to be analogous to precipitated vegetable gluten, 

 combined with some of the colouring extract. 



13. Pure ammonia and carbonate of ammonia readily 

 act upon the coloining matter of lac, but do not completely 

 dissolve the entire substance. 



£To be continu'.d.] 



X.XII. Experiments and Ohservations on Feathers, and the 

 Down of domestic Fowls. By AK Parmentieu, 



[Continued from page 217.] 



Swans' Down or Feathers. 



Among the wild swans, there are some the plumage of 

 which is entirely white, like that of domestic swans : others, 

 and this is the case with the greater number, are rather gray 

 than white ; and this gray is of a darker colour on the head 

 and back, so that it appears almost brown. 



Domestic swans are stripped of their feathers twice a year, 

 in the same manner as geese. They furnish a down much 

 sought after on account of its softness, and which is enw 

 ployed for stuffmg pillows and beds. It is well known also 

 that the same substance, exceedingly fine, and softer than 

 silk, is used for powdering-puffs : it is formed also into 

 beautiful muffs and fur articles, which are both light and 

 warm. The feathers of the wings are preferable to those o|" 

 tUegooae for writing, and fcr the tubes of painting^brushes. 



