TRANSACTIONS OF THE SECTIONS. 17 
hydrogen is replaced by one equivalent of oxygen. It is a beautiful 
white crystalline compound melting at 49° ¢., and is soluble both in 
alcohol and zther. The combination of the acid with oxide of glyceril 
exists in the butter; it unites with metallic oxides and forms salts: these 
were described, but the results are not susceptible of analysis, as they 
were principally numerical. The formula of the acid is C,, H,, O;. 
On a New Mode of estimating Nitrogen in Organic Analysis. By 
Professor Bunsen, of Marburg. 
The qualitative methods at present employed for the analysis of 
azotized bodies were shown to be defective; for it is impossible to 
employ these processes when the nitrogen and the carbon are in small 
proportions to each other. Professor Bunsen’s process consists in in- 
troducing the substance to be analysed, after having mixed it with 
oxide of copper, into a glass tube. A few slips of metallic copper are 
then added, and the tube is fixed to Dobereiner’s apparatus for produc- 
ing hydrogen. This gas is conducted through it until all the atmos- 
pheric air is expelled, the tube having given to it a rotatory motion at 
the same time, in order to dislodge any air which might be retained be- 
tween the particles of the oxide of copper. The tube is now hermeti- 
cally sealed, and introduced into an iron vessel filled with gypsum. The 
gypsum must be still moist when the tube is introduced, in order that 
it may be firmly wedged. Thus prepared, it is introduced into the 
common oven used for organic analysis, and surrounded with red-hot 
coals. If the tube be of strong green glass it never bursts. When the 
combustion is completed the tube is placed below a graduated glass 
receiver standing over mercury, and the point cut off. The gas, which 
had a pressure of several atmospheres, now rushes into the jar. The 
carbonic acid is absorbed by a ball of hydrated potash, which is intro- 
duced into it, and the remaining gas must be nitrogen, for all the 
hydrogen must have been converted into water by the oxygen of the 
oxide of copper. The results obtained by this method agree with 
theory to the second, and often to the third decimal place. 
On the Compound or Radical called Kakodyl. By Professor Bunsen, 
of Marburg. 
The object of this paper was to describe a new radical resembling 
alcohol, in which arsenic replaced the oxygen of that compound. This 
radical enters into numerous combinations, forming, with oxygen, a 
peculiar acid, called kakodylic acid. The oxide of kakodyl has so 
great an affinity for oxygen, that when exposed to the air it imme- 
diately inflames. The bodies produced by the combustion are arseni- 
ous acid, carbonic acid, and water. By the further oxidation of the 
oxide of kakodyl, kakodylic acid is produced. The sulphuret of kakodyl 
is similar in composition to the oxide, and participates in many of its 
properties. The telluret, selenuret, iodide and bromide of kakodyl 
