lxxxvi GENERAL SUMMARY OF SCIENTIFIC AND 



narily no disturbance of the digestive organsr It lias been 

 used with good effect in nervous affections, even in cases of 

 loner standing. 



Hesse lias published a valuable investigation giving the 

 exact data concerning the rotatory power of a large number 

 of organic bodies including the sugars on polarized light. 



Kreusler has negatived the assertion of Eaoult that pure 

 cane sugar in aqueous solution, without the presence of air 

 or ferments, but solely by the action of light, became invert- 

 ed and yielded glucose. Solutions of various strengths were 

 sealed up in vacuo, and were exposed to direct sunlight when- 

 ever possible for eleven months. Not a trace of glucose could 

 be detected. In presence of air, however, some glucose is 

 formed ; and to this fact the author attributes the results 

 obtained by Raoult. 



Gautier has effected an important synthesis likely to prove 

 of practical value. He has succeeded in uniting two mole- 

 cules of dextrose by abstracting from them a molecule of 

 water, thus forming a substance having the composition of 

 the compound sugars. The result was accomplished by the 

 action of hydrochloric-acid gas on the dextrose dissolved in 

 absolute alcohol. A substance was obtained which was more 

 analogous to gum and dextrin than to sugar in appearance 

 and taste, but which yielded again a simple sugar on heat- 

 ing, though this appeared not to be dextrose again, but to be 

 analogous to, if not identical with, inosite. 



Giraud has given an analysis of gum-tragacanth, by which 

 it appears that sixty per cent, of it is a pectic compound ap- 

 parently identical with the pectose of Fremy, existing in un- 

 ripe fruits and in turnip roots, etc. Pectic acid and pectin 

 were both prepared from the gum. The other constituents 

 are water, twenty per cent. ; soluble gum, eight to ten per 

 cent. ; cellulose, starch, and mineral matters, each three per 

 cent. 



Keichardt has prepared from the thoroughly exhausted 

 beet-root pulp a new carbohydrate isomeric with Scheibler's 

 arabinic acid, which he calls pararabin. The pulp consists 

 of 38.5 per cent, arabinic acid, 54 per cent, pararabin, and 

 7.5 per cent, cellulose. 



Hofmann has examined a new red coloring matter, brought 

 into commerce within a few months under the name of eosin. 



