i 2 
4 
O. Loew on the action of water upon Carbohydrates. 371 
Art. XLITI.—On the action Hi water upon “ ete sage ital at an 
elevated temperature; by O. 
It is well known that the carbohydrates ar not decomposed 
with separation of carbon, at a temperature of 170°C. Cane- 
sugar yields at 160° levulosan and glucose, at “180° caramelan, 
at 200° caramel, assamar and caramelin, and at about 250° it 
yields with total decomposition aldehyd, aceton, acetic acid, fur- 
furol and carbon. But the decomposition takes place quite dif- 
ferently if water is present. While dried sugar yields only le- 
deans and glucose at 160°, it is perfectly deco — on heat- 
ng with water in sealed tubes at the same tempera 
“This decomposition is accompanied with the pita of 
carbonic acid and separation of carbon. Very nearly half of 
the carbon contained in the sugar employ yed is thus separated. 
If the black mass contained in the tube, which has a strong acid 
vos tes is distilled with water and the distillate saturated with 
carbonate of lead, and evaporated, a salt is obtained giving all 
the SS reactions of formic acid. I obtained the fol- 
cores results on analysis: 
800 grm. gave 0593 anes of lead, 0°728 grm. gave 
0 21000, and 0°046 wate 
Calculated. Found. 
Pb 69°69 69°84 : 
C 8-08 7-87 } =Formiate of lead. 
H 0°66 0°69 
There is also formed in this reaction a small quantity of humic 
acid. 
The specific action of the water in this decomposition seems 
to be that of an acid; for if sugar be hea ted with alcohol at the 
ed; not the smallest quantity of carbon is an ; Farther 
the same sence upon other  earbohy agate 
Ee ak or milk-sugar heated with water to 170° for about 
five hou gives formic acid, carbon and carbonic “aids i gum 
yields the most carbonic acid. There is also form | 
acid, Pat little soluble in water, though easily in ses Rg: id 
ether. I propose to make this acid the object of further. 
oy 
pay 
