146 
SELECTED ARTICLES. 
this state it crystallizes in long needles, and much resembles 
sublimed benzoic acid. 
It is slightly sweet to the taste, irritates the throat, strongly 
reddens litmus paper, and decomposes the alkaline carbonates 
with the disengagement of carbonic acid. 
Concentrated sulphuric acid put in contact with salicylic 
acid, does not produce any change when cold ; when heated, 
the mixture blackens and gives off sulphurous acid. 
Concentrated nitric acid does not alter salicylic acid when 
cold, but as soon as heat is applied a rapid reaction takes place, 
accompanied with a copious disengagement of gas. At the 
commencement, the liquor is strongly colored yellow, but in a 
short time it becomes pale; evaporated to a syrupy consistence, 
it is almost without color. By, rest it deposits small yellow 
crystals of a very bitter taste. The color of the aqueous so- 
lution is deeper than that of the solid matter. This product 
of the action of nitric acid upon salicylic acid appears to be 
identical with that obtained by the same means from hyduret 
of salicyle. But of this I am not sure; the smallness in quan- 
tity of matter upon which I operated, prevented me from de- 
ciding this point. 
Salicylic acid contains an atom of water, which it loses 
when it combines with bases. Its formula is C 28 H 10 O 5 +H 2 O. 
The following are the results of its analysis: 
I. 0.307 of the crystallized acid gave 0.140 water and 0.678 
carbonic acid. 
II. 0.350 of the same gave 0.140 water and 0.775 carbonic 
acid. 
Which is, in hundredths — 
Theory, 
Experiments, 
A 
I. 
II. 
C 28 
H 12 
0° 
1070.16 
74.88 
600.00 
61.32 
4.29 
34.39 
61.16 
4.41 
34.43 
61.27 
4.43 
34.33 
1745.04 
100.00 
100.00 
100.00 
