424 Scientific Intelligence. 
eral purifications are required to separate a solid fat which is entirely 
inodorous ; the true aromatic substance is a mixture of two oils, one 
probably an alteration of the other. This oil, upon which the flavor of 
the coffee depends, is but the -0002 of the berry; it is not surprising, 
nn that a single drop diffuses the odor of coffee throughout a 
‘oom 
yen gives a curious calculation of the value of this aroma, by 
which it chi that about one thousand dollars per. pound is paid for 
G. C. 8. 
Will’s process for estimating nitrogen. When the substance to be ana- 
lyzed contains a small proportion of nitrogen and much hydrogen, @ 
larger quantity of the substance must be taken to obtain a sufficient 
mount of ammonia. Much water is of course formed, and this conden- 
sing in the cooler parts of te tube, forms a pasty mass with the soda- 
lime — forms plug in the front end of the tube, and spoils the analy- 
sis, or at the drawn-out end prevents the removal of all the ammonia, so 
that as pn as one-third may be lost. ‘To avoid this difficulty, four 
parts of lime to one of hydrate of soda are to be used, instead of the 
usual proportion of two to one. The end, instead of being drawn up 
abruptly, is to be drawn out for about a quarter of an inch, and then up- 
wards, so .as to form a segment of a circle. In loading the tube, about an 
inch of coarsely powdered lime is to be introduced before the mixture. 
= emp also points out the ammonia floa — in the air, as a source 
a On the Brocton of Caustic Baryta; by Dr. BE. Rr BEL, 
(Chem. Gaz., Nov., 1846.)—The author gives the ageless 6 to the 
ar 
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“it ogen not a Constituent of cot meget ; ErpMaNnNn and 
MarcHann, (quoted in Jour. de Pharm. et de Chim., ix, p. 470. )—Liebig 
has asserted, when speaking of the vegetable alkalies, that “ no reme ys 
devoid of nitrogen, possesses a poisonous action in a similar dose 3” > and 
adds that this consideration led to the re-examination of picrotoxine, 
y Mr. Francis, who ascertained that nitrogen did exist in it. 
This being contrary to the analysis of several distinguished ¢ chemists, 
Messrs. Erdmann and Marchand pre examined the subject with the 
greatest care. The test of M. Lassaigne, which, as is well known, is 
exceedingly delicate, failed to give any indication of ae pooeree 
nitrogen. The ordinary mode of combustion was then tried, 
gramme of em substance being burned onih time. Tad the pic j 
contained half of one per cent. of nitrogen, there would have been 
collected 4 cub. cent. of that gas. In two experiments, they © 
