338 INOSIT. FERMENTS. INORGANIC SALTS. [BOOK I. 



brown colour when boiled with solutions of the caustic alkalies ; it 

 does not reduce Fehling's solution, but changes its colour to green. 



Scherer's When inosit is treated with nitric acid, the solution 



reaction. evaporated nearly to dryness, then moistened with 



ammonia and a small quantity of calcium chloride, and again evapo- 

 rated, a rose-red colouration is produced. Scherer's test only succeeds 

 with nearly pure inosit. 



Gaiiois' When a solution containing inosit is evaporated, at 



reaction 1 . a gentle heat, nearly to dryness, then treated with 



a small drop of solution of mercuric nitrate (the solution used in 

 Liebig's method for the estimation of urea answers very well) and 

 evaporated carefully to dryness, a yellowish white residue is obtained; 

 on further cautiously heating, the yellow changes to a deep rose- 

 colour, which disappears on cooling but reappears on again heating. 

 This constitutes a delicate and characteristic reaction, helping to 

 confirm the presence of inosit, the identification of which should 

 however depend also upon a knowledge of the conditions under which 

 the body was obtained, and upon such properties as crystalline form, 

 solubility, sweetness, &c. 



Inosit yields when treated with nitric acid nitro-substi- 

 of inosit tution compounds which are soluble in alcohol and have the 



composition C 6 H 6 (NO 2 ) 6 O 6 (Hexanitroinosit) and C 6 H 9 (NO 2 ) 3 O C 

 (Trinitroinosit) ; these bodies explode when struck. 



In the presence of decomposing proteids, inosit is decomposed, with the 

 formation of propionic, butyric and ordinary lactic acids (Yohl). 



Proportion As has previously been stated, inosit is not an invari- 



of inosit in able constituent of muscle. According to Jacobsen, 

 Muscle. horse flesh contains 0'003 per cent, of inosit. 



The Ferments present in Muscle. 



Muscle contains a trace of pepsin, as was shewn by Briicke. It is 

 perhaps in consequence of its presence that muscle so readily dis- 

 solves in very dilute hydrochloric acid. Dead muscle also contains an 

 amylolytic ferment which readily converts the muscle-glycogen into 

 sugar. Other hypothetical ferments have been surmised to exist in 

 order to explain the processes going on in muscle during activity 

 and rigor, 



THE INORGANIC CONSTITUENTS OF MUSCLE. 



The proportion of water in muscle varies between 



74 and 80 per cent., the average being about 75. It is 



said to be larger in young than in adult animals. The muscles of 



cold-blooded animals contain more water than those of warm-blooded 



animals. 



1 Gallop De VInosurie, Paris, 1864. The Author has been unable to consult 

 this Memoir. 





