FIBRINE. 117 



potash, and acetate of lead is added to the solution, in 

 such proportion that the whole of the oxide of lead 

 remains dissolved in the potash, the mixture, if heated 

 to the boiling point, becomes black like ink, and sul- 

 phuret of lead is deposited as a fine black powder. 



It is extremely probable, that by the action of the 

 alkali the sulphur is removed as sulphuretted hydrogen, 

 the phosphorus as phosphoric or phosphorous acid. 

 Since, in this case, sulphur and phosphorus are elimina- 

 ted on the one hand, and oxygen and hydrogen on the 

 other, it might be concluded, that fibrine and albumen, 

 when analyzed with their sulphur and phosphorus, would 

 yield a larger proportion of oxygen and hydrogen than 

 is found in proteine. But this cannot be shown in the 

 analysis ; for fibrine, for example, has been found to 

 contain 0-36 per cent, of sulphur. Assuming, then, 

 that this sulphur is eliminated by the alkali in combina- 

 tion with hydrogen, proteine would yield 0'0225 per 

 cent, less hydrogen than fibrine ; instead of the mean 

 amount of 7*062 per cent, of hydrogen, the proteine 

 should yield 7'04 per cent. In like manner, by the 

 elimination of the phosphorus in combination with oxy- 

 gen, the amount of oxygen in fibrine would be reduced 

 from 22-715 22-00 per cent, to 22-5 21-8 per 

 cent, in proteine. But the limits of error in our analy- 

 ses are, on an average, beyond ^th per cent, in hydro- 

 gen, and beyond T 4 ths per cent, in the oxygen ; while 

 in the supposed case the difference in the hydrogen 

 would not be greater than ^th per cent. 



Finally, if we reflect, that the elimination of oxygen 



