

Chemistry and Physics. 109 



various products obtained from the caseine. There is then, a perfect 

 similarity between the products of the oxydation of all these bodies; 

 the author observed that the amount of volatile products was increased 

 when the organic substances were allowed to digest for some time with 

 the sulphuric acid, which shows that the acid acts by breaking up the 

 compound into different organic groups. 



The author observes that he has obtained acetic aldehyde by treating 

 milk-sugar with chromic acid, and that Engelhardt has observed it in 

 the distillation of lactate of copper. 



[These researches show an identity between the products of the de- 

 composition of gelatine and the so-called proteine bodies by oxydizing 

 agents ; to which is to be added the fact that both of them afford leu- 

 cine by alkalies and acids, and according to Berzelius, both yield malic 

 (saccharic?) acids, by the action of nitric acid. The difficulties pre- 

 sented in determining the composition of these substances by direct 

 analysis are very great, from the absence of any test of their purity ; 

 from their constant tendency to decomposition rendering it impossible 

 to boil them in water, or even dry them without change, and from the 

 presence of variable and often considerable portions of sulphur and 

 phosphorus, which are only in part separated by the action of alkalies. 

 The immense number of analyses performed, and researches which 

 have been made, and the various disputes upon the subject which have 

 vexed the chemical world, have left us no wiser than before. 



In a late communication,* I attempted to show that gelatine may be 

 regarded as an azotized derivation of cellulose, dextrine or some iso- 

 meric body, and that a formula agreeing at once with the results of its 

 decomposition and the various analyses, isC 24 H O0 N 4 8 =C O4 H 20 20 



+4NH 3 -12Hat 



The complete similarity between the decomposition of gelatine and 

 the proteine bodies by deoxydizing agents, suggests the idea that the lat- 

 ter are likewise derivatives'of cellulose. The sulphur and phosphorus 

 so variable in their proportions as they are found to be, can scarcely be 

 regarded as Mulder has represented them, elements bearing an equiva- 

 lent ratio to the oxygen, carbon, hydrogen and nitrogen, while the 

 affinity by which they are retained, tends to show that they still make 

 an integral part of the combination. They are, it appears to me, to he 

 viewed as replacing in part the oxygen and azote of the normal com- 

 pounds in the same way as minute portions of magnesium or strontium 

 m ay replace the calcium in calcite and arragonite, or arsenic the phos- 

 phorus in pyromorphite. In calculating formulas from analyses, 16 

 parts of sulphur should then be regarded as equivalent to 8 of oxygen, 

 and 31*7 f phosphorus to 14 of azote. Supposing the normal com- 

 pound to be equal to one equivalent of cellulose, with three of ammo- 

 n, a minus twelve of water, we have the formula C., 4 H 17 N 3 O g (= 

 C 24 H 2 O 20 +3NH 3 ~C 24 H 17 N,O 8 +I2FW4 The results obtained 





See this Journal, Jan., 184S, p. 70. f Ibid, 



t The formula of cellules . sugar, and all the allied compounds, must evidently 

 be regarded then, as C, 4l Ac, if we take the equivalent of hydrogen ns 12-5, oxy- 

 gen being 100; these compound! are well known to be pnlybasic. The formation 

 °f an amide by the elimination of 4110 for one equivalentof ammonia, is analogous 

 t0 the reaction by which the nitrites are derived from monobasic .moniacal salt 

 °_f cyanogen from oxalate of ammonia, constituting the anhydrid atnids of M. 



torbftrdt. 



