198 ANIMAL AMIDES. 



Carbon, . 54-393 



Hydrogen, . 6-963 



Azote, . 15-783 

 Oxygen, ^ 



Sulphur, 22-861 

 Phosphorus, ) 



100- 



Numbers which agree exceedingly well with the result of 

 Mulder's analyses. We may therefore conclude that fibrin is a 

 compound of ten atoms protein, with one atom sulphur, and one 

 atom phosphorus, or 10 (C 40 H 31 Az 5 O 12 ) + S + Ph. 



SECTION V. OF FIBRIN FROM SILK. 



This species of fibrin has been examined with much ingenuity 

 and skill by M. Mulder.* Raw silk was boiled successively in 

 water, alcohol, ether, and acetic acid, till every thing soluble in 

 these liquids was removed ; what remained was considered as 

 fibrin. In yellow raw silk it amounted to 53-37, and in white raw 

 silk to 54 '04 per cent, 



Its colour is white, but it is much softer and more brittle than 

 natural raw silk, and has much less coherence. So that a tuft of 

 it breaks with the greatest facility into an infinite number of very 

 minute threads, spreading out in every direction. Hence neither 

 so beautiful nor so strong a fabric could be woven of it, as of raw 

 silk in its natural state. 



It is heavier than water. When burnt it emits the smell of horn. 

 When distilled it gives much carbonate of ammonia, empyreu- 

 matic oil, and water, and leaves a bulky charcoal. When thrown 

 upon a red hot plate of iron it melts, or at least becomes soft, 

 swells out, and burns with a light blue flame, and leaves a bulky 

 charcoal. 



It is insoluble in water, alcohol, ether, and acetic acid. It is 

 equally insoluble in fat and volatile oils. It dissolves immedi- 

 ately in concentrated sulphuric acid at the common temperature 

 of the atmosphere, forming a light brown thick solution. When 

 heated it becomes first of a beautiful red, then of a brown, and 

 finally of a black colour, while sulphurous acid is given off. 

 From this solution it is not thrown down by water. But when 



* Poggendorf's Annalen, xxxvii. 603, and xl. 266. 



