108 INOSIT. 



The formation of the compounds of glycuronic acid, to which 

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

 There can be little doubt that the acid has its origin in the carbo- 

 hydrate (dextrose) of the body, but it is not yet possible to ex- 

 plain exactly how each particular compound arises after the 

 introduction of the corresponding substance into . the animal 

 organism. 1 



Inosit. C C H 12 6 + 2H 2 0. [CH.OH] 6 . 



This substance has the same percentage composition as a sugar, 

 and possesses a distinctly sweet taste; in virtue of which prop- 

 erties it appears to have been usually classed with the carbo- 

 hydrates. 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 Struc- 

 turally it may be represented by a closed ring of six CH . OH 

 groups. 



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

 originally by Scherer 3 in the muscles. Cloetta showed its pres- 

 ence 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 conven- 

 iently 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 filtrate from these is then precipitated with normal 

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

 this filtrate 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) ; 



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

 - Compt. 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 Vohl, Ibid. Bd. xcix. (1856), S. 125 ; ci. S. 50. 

 ? Kiilz, Centralb.f. d. med. Wiss. 1875, S. 933. 



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

 cxvii. S. 118. 



