438 H. B. Hill—Eithers of Urie Acid. 
first, the monobasic character of urea, and secondly Wanklyn 
and Gamgee’s oxidation with alkaline permanganate. 
As for the basicity of urea, Heintz* has already shown that 
basicity does not always correspond to the number of amide 
nitrogen atoms, and that amidogen, like hydroxyl, is largely 
. 
dependent for its character upon the nature of the radical to 
which it is attached. As especially pertinent he instances ox- 
amide, which is neutral although undoubtedly a diamide, An 
entirely different case in its nature, although perhaps still more 
to the point is guanidine C NH, which is monobasic only. Ac- 
2 
cording to every analogy, therefore, the observed basicity of 
urea is but the normal behavior of carbamide 
The experiments of Wanklyn and Gamgeet were five im 
number. T'wo were made upon urea, two upon ammonium 
salts, and one upon acetamide. They found with an excess of 
permanganate that urea gave up all its nitrogen as gas, while 
the nitrogen of the ammonia and of acetamide was oxidized to 
nitric or nitrous acid. It may well be questioned, I think, 
whether these results are sufficient to form the basis of any 
generalization as to the behavior of ‘‘admitted amides,” still 
granting that urea is thus distinguished from all other amides 
the proof is yet to be brought that the formula C NH_ possesses 
any advantages in explaining this observed decomposition. What 
experimental facts, what analogies, what plausible theory eve? 
can be given to justify the assumption that the nitrogen atoms 
in cont: and CNH, under the conditions employed by 
- 2 OH . 
Wanklyn and Gamgee, would differ so fundamentally in their 
urea may be, 
it certainly is not to be explained by so simple a device as the 
substitution of one imide nitrogen for an amide. If this anom- 
alous behavior should be established by further investigation 
of other diamido compounds, it would not be the first case in 
which the mono-carbon compounds differed essentially from 
1 
have thus bred given my reasons for dissenting from 
Professor Mallet’s assertion that the structure of urea is by ne 
means settled. I can not but think it established by oleae 
as unequivocal as our present methods of research are cap 
of givin 
* Loe. cit. p. 74. + Journ. Chem. Soc., 1868, p- 25. 
Harvard College Laboratory, Sept., 1876. 
