ELEMENTS OF COMPOSITION. 



33 



quantity, in a peculiar disease known as diabetes mellitus. In this 

 affection it is found in the urine and most opposite fluids of the body. 



Inosite or Muscle Sugar, C 6 H 12 6 + 2H 2 . 



This substance, discovered by Scherer, is identical with the phaseoman- 

 nite first found in beans by Vohl, and subsequently, extensively distri- 

 buted through the animal kingdom. 



Inosite (fig. 8.) forms clinorectangular prisms, which lose at 100 C. 

 two molecules of water of crystallization, efflorescing in the air. From 

 its solution in boiling alcohol it separates in brilliant scales. It is easily 

 dissolved in water, and undergoes fermentation with cheesy substances, 

 generating so lactic and butyric acids. 



The plane of polarisation is not affected by it, nor does it reduce sul- 

 phate of copper. On the other hand, 

 when evaporated almost to dryuess 

 with nitric acid, and then treated with 

 ammonia, it becomes of a lively rose- 

 red colour on being again evaporated, 

 especially when chloride of calcium is 

 present. 



Inosite is widely distributed through- 

 out the body. It is met with in the 

 juices of the muscle of the heart, in 

 the muscles of dogs, in the pancreas 

 and thymus (Scherer}. It has been 

 also found by Cloetta in the lungs, 

 kidneys, spleen, and liver, and finally, 

 by Mutter in the substance of the brain, 

 and by Holm in the suprarenal capsules 

 of the ox. Inosite may also pass off by 

 the urine, as in diabetes and Bright s disease (Cloetta, Neukomm)^ 



It is, without doubt, a decomposition product of histogenic substances. 



Sugar of Milk, C la H M 11 + H a O. 



This compound is distinguished from that just mentioned by its che- 

 mical composition, as well as its crystallization in oblique four-sided prisms 

 (tig. 9), and lower degree of solubility in water. It polarises a ray of light 

 also to the right, and reduces oxide of copper 

 like grape-sugar. Sugar of milk, like inosite, is 

 converted by cheesy and other ferments into 

 lactic and butyric acids. 



Milk-sugar is not found in the vegetable 

 kingdom, but is a constituent of mammalian 

 and human milk. Its quantity in this fluid 

 stands in proportion to the amount of carbo- 

 hydrates introduced into the system, and yet 

 it is not absent in the milk of the carnivora 

 after an exclusively fleshy diet, as Bensch has 

 shown in confutation of Dumas' statements. 



It has not yet been demonstrated in the blood of mammals with cer- 

 tainty, and appears not to exist there. 



Sugar of milk, therefore, is probably generated by the (fermenting 1 ?) 



Fig. 8. Inosite, from the muscle of the human 



Fig. 9 Sugar of milk. 



