498 
SECOND REPORT— 1832 . 
elements in a large class of vegetable compounds. In sugar, 
gum, and starch of different kinds, he has shown that the oxy¬ 
gen and hydrogen exist in the same proportion as in water, and 
therefore suggests that such substances may in reality be com¬ 
pounds of water and carbon. Such views are valuable as well 
as interesting when they are drawn as deductions from a large 
number of analytical results, as those of Dr. Prout are; but they 
are, on the other hand, productive of much mischief when they 
are adopted on theoretical grounds, and experiments afterwards 
instituted to confirm them. 
Are the vegetable acids oxides of compound radicals ?— 
3°. A third thoretical view, not destitute of probability, is 
that which represents the organic acids as oxides of a com¬ 
pound radical. Thus, if we put 2 C + O —R, a supposed radi¬ 
cal, we have 
R = Mellitic acid. 
R = Carbonic oxide. 
R = Oxalic acid. 
at* 
R —Carbonic acid. 
But there are difficulties attending this representation of 
the constitution of these compounds. Carbonic oxide contains 
more oxygen than mellitic acid, while oxalic the stronger con¬ 
tains less oxygen than carbonic the weaker acid. It is not un¬ 
likely that future researches may supply us with a more satis¬ 
factory mode of obviating these difficulties than we are yet ac¬ 
quainted with. 
Again, if we take C + J H = R, we have the base of the follow¬ 
ing suite of acids. 
Citric acid . . = R 
Tartaric acid. . =4R + 5Q 
Formic acid — R 
Succinic acid = 4 R + 3 O 
Pyrogallic acid =6 R + 3 O 
Tannin. =6R+4<0 
The crystalline compound discovered by Opperman as the 
base of artificial camphor = 4 C + 3 H. If we represent this by 
R, we have 
R ..... . —Acetic acid. 
3 R + O . . . —Camphor. 
3 R + (Cl + H) = Artificial camphor. 
•• 
R ..... . = Camphoric acid. 
It is very interesting by means of such formulae to compare 
the atomic composition of bodies possessing properties so dif¬ 
ferent. That the acetic and camphoric acids are oxides of the 
