Nitrogen contained in Alimentary Substances. 359 



of ammonio-chloride of platinum, equal to 12*48 per cent, of 

 nitrogen. 



LIII. 0*384; grm. of the purified fibre of pork-ham gave 

 0*860 grm. of ammonio-chloride of platinum, equal to 14*21 

 per cent, of nitrogen. 



We regret that at the time when these experiments were 

 made, we were unable to procure fresh pork, but we thought 

 that an examination of the salted and smoked substance would 

 not be devoid of interest. 



From these results we see that there is no appreciable 

 change produced in the composition of the fibre by the pre- 

 paration and length of time it had been kept; if however we 

 take equal weights of the prepared ham and of the fresh flesh 

 of the sow, we shall of course find a considerable difference 

 in the amount of nitrogen from the large quantity of salt which 

 is present in the prepared ham. We conclude this account 

 of our experiments by giving the analysis of the white of the 

 e^g of the barn-door fowl. 



LIV. 0*369 grm. of the white of the egg gave 0*781 grm. 

 of ammonio-chloride of platinum, equal to 13*44 per cent, of 

 nitrogen. The quantity of nitrogen in pure albumen, as de- 

 termined by Mulder, is 15*8 per cent. 



We take the liberty to add to these experiments the follow- 

 ing remarks: — The proportion of nitrogen in purified mus- 

 cular fibre seems to be identical, from whatever part of the 

 animal kingdom it may be obtained ; and the differences given 

 by the results of analysis may be fully explained by the diffi- 

 culty, or even impossibility, of analysing it in an equally pure 

 or impure condition, as obtained from different animals, in 

 which it is always mixed with cellular tissue, minute vessels 

 and nerves. Moreover, it is extremely difficult to get rid of 

 traces of fat and hematine. 



That the chemical properties of muscular fibre in the whole 

 animal kingdom are identical, one of us endeavoured to prove 

 in a former research (Schlossberger, Vergleichende (Jnter- 

 suchungen icber das Fleisck verschiedener Thiere. Stuttgardt, 

 1840). In contradiction to a very generally-received opi- 

 nion, it appears to us that the muscles of fish are as rich in ni- 

 trogen as those of higher animals; at first sight, however, owing 

 to the presence of a greater quantity of water, and in some 

 fishes, as the eel, to a difficultly separable fat, its amount ap- 

 pears very much lower. Further, as the proximate principles 

 are essentially the same in both classes of animals, it seems 

 to us that they should be equally nutritive, although this pro- 

 position is also directly opposed to another very general pre- 

 judice. According to our scale, the oyster does not seem 



