108 INOSIT. 



attention has been drawn is of great and increasing interest. There 

 can be little doubt that the acid has its origin in the carbohydrate 

 (dextrose) of the body, but it is not yet possible to explain exactly how 

 each particular compound arises after the introduction of the corre- 

 sponding substance into the animal organism 1 . 



Inosit. C 6 H 12 O 6 -f2H 2 O. [CH.OH] 6 . 



This substance has the same percentage composition as a sugar and 

 possesses a distinctly sweet taste, in virtue of which properties it 

 appears to have been usually classed with the carbohydrates. It does 

 not however yield any of the reactions most typical of this class of 

 substances; for instance it exerts no rotatory power on polarised 

 light, does not reduce metallic salts, does not undergo alcoholic 

 fermentation and does not react with phenyl-hydrazin. On account of 

 these peculiarities the view was long ago expressed that it is not a 

 carbohydrate at all, and this has recently been shown to be the case 

 by Maquenne who has proved that it belongs really to the benzol 

 series 2 . Structurally it may be represented by a closed ring of six 

 CH . OH groups. 



Inosit occurs but sparingly in the human body ; it was found 

 originally by Scherer 3 in the muscles. Cloetta showed its presence in 

 the lungs, kidneys, spleen and liver 4 , and Miiller in the brain 5 . It 

 occurs also in diabetic urine, and in that of 'Bright's disease,' and 

 is found in abundance in the vegetable kingdom, more especially in 

 unripe beans from which it may be conveniently prepared 6 . It is also 

 found in the urine after the ingestion of an excess of water into the 

 body 7 . 



It is prepared from aqueous extracts of the mother tissues by 

 acidulating with acetic acid and boiling to remove any coagulable 

 proteids. The nitrate from these is then precipitated with normal 

 lead acetate and filtered, and the inosit is finally precipitated from this 

 nitrate by means of basic lead acetate in presence of ammonia. The 

 lead compound is decomposed with sulphuretted hydrogen and after 

 the addition of alcohol and ether to the solution inosit separates out by 

 crystallisation 8 . 



Pure inosit forms large efflorescent crystals (rhombic tables) ; in 



1 In the case of camphor and chloral see Fischer u. Piloty, loc. cit., S. 524. 



2 Campt. Rend. T. civ. (1887), pp. 225, 297, 1719. 



3 Ann. d. Chem. u. Pharm. Bd. LXXIII. (1850), S. 322. 



4 Ibid. Bd. xcix. S. 289. 



5 Ibid. Bd. cm. S. 140. 



6 Void, Ibid. Bd. xcix. (1856), S. 125 ; ci. S. 50. 



7 Kiilz, Centralb. /. d. med. Wiss. 1875, S. 933. 



8 Harms', Ann. d. Ch. u. Pharm. Bd. cxxix. S. 222. See also Boedeker, Ibid. Bd. 

 cxvu. S. 118. 



