Product of action of Nitric acid on. Woody Fibre. 21 
possible he conceives himself to have proved, by subjecting woody 
fibre to the action of nitric acid, the product of such action being a 
substance which he regards as pectic acid. From this in connec- 
tion with other circumstances, he infers the probability of the 
same change under the influence of certain agencies in the living 
plant. The grounds presented by Prof. Sace for believing that 
the substance above mentioned was pectic acid, are scarcely suffi- 
cient. The object of the present investigation, ane at 
the suggestion of Prof. Liebig, was to decide this 
Prof. Sace’s process was repeated, and the sie of the sub- 
stance obtained were compared with those of the substance ac- 
knowledged as pectic acid, obtained from aeenipa: The latter 
was prepared according to the method of Chodnew 
2UU grammes shavings of white pine were oe some hours 
with 2 kilogrammes nitric acid of commerce and 400 grammes 
distilled water, and the white pasty mass that resulted washed | 
out with water, likewise distilled. Prot. Sace found a sample of 
the mass thus obtained, perfectly soluble in dilute ammonia, and 
it was this substance dried at 212° F. that he subjected to analy- 
sis. ‘The mass obtained by myself was not perfectly soluble in 
Water containing ammonia. A substance of syrupy consistence 
remained in small quantity upon the filter. ‘The whole ayers 
was therefore treated with ammonia and the solution filtere 
afterwards precipitated by hydrochloric acid. The onaatileaia 
was washed out, at first with slightly acidified water, then with 
pure water and finally with alcohol. After pememy drying at 
212°, this substance was of a reddish gray colo 
Adi fference in its behavior and that of the ‘pecite acid from 
turnips is observable on washing out with aleohol—the latter be- 
comes fibrous on being primed with the hand ; the former retains 
its slimy consistence. 
The following are the felts of the comparison of the two 
Substances dried at 21 
The pectic acid is slightly soluble in boiling water and its solu- 
tion coagulable by sugar or alcohol. The substance from w 
is on the contrary insoluble 1 in water. 
he pectic acid is easily soluble in alkalies and reprecipitable 
by acids as a perfectly transparent jelly. The substance from 
Wood is difficult of celsdch in alkalies, and the precipitate, at first 
transparent, contracts rapidly to white translucent flocks. From 
a solution more strongly alkaline it is pean as a light white 
powder ; this was not the case with the acid. 
The alkaline solutions of both i a Be are precipitable by 
alcohol. Either substance boiled with excess of potas ash loses 
after a time its property of being precipitated by acids. 
* Annalen der Pharmacie, li, 355. 
