214 ? Mons. R. Piria on the Combinations of Salicyle* 
coliol. When quite dry it undergoes no change by exposure 
to the air, but when wet it absorbs oxygen, becomes covered 
with numerous green spots, which ultimately turn black ; the 
whole mass becoming eventually a black sooty powder, which 
will be alluded to in the course of these remarks on account 
of a peculiar acid which it contains. 
A solution of salicide of potassium is precipitated yellow 
by salts of lead, silver, mercury, manganese, and barium. 
Salicide of ammonium is procured by mixing liquid ammonia 
with the hydruret of salicyle, in the same manner as the cor- 
responding salt of potassium. It crystallizes in yellow needles, 
and by exposure to the air is soon decomposed into its con- 
stituents, ammonia being copiously evolved. 
Salicide of barium is obtained by precipitating a solution 
of salicide of potassium by chloride of barium. It may be 
obtained in minute needles, but is very slightly soluble in 
water. It consists of 
Carbon .... 
Atoms. 
84 
Theory. 
40*93 
Exp. 
41*15 
Hydrogen , 
... 7 
7 
3*34 
3*41 
Oxygen.... 
... 6 
48 
22*96 
22*57 
Barium .... 
68 
32*77 
32*87 
Atomic 
weight... 
207 
100 
100 
it hence contains two atoms of water, and when dried in Lie- 
big’s desiccating apparatus, it gives up this quantity, 1*237 
parts losing 0*110 parts of its weight. 
Salicide of copper may be prepared by dissolving freshly 
precipitated oxide of copper in hydruret of salicyle, and eva- 
porating to dryness over a water bath ; it forms a light yellow 
powder, which, when heated, partly sublimes in iridescent 
scales. Submitted to analysis, it was found to consist of 
Carbon .... 
Atoms. 
84 
Theory. 
55*50 
Exp. 
55*75 
Hydrogen . 
.. 5 
5 
3*24 
3*47 
Oxygen .... 
32' 
20*74 
20*70 
Copper .... 
32 
20*52 
20*08 
Atomic 
weight... 
153 
100 
100 
Salicic Acid. 
This compound may be obtained by heating hydruret of 
salicyle with an excess of potass. The mixture becomes deep 
reddish-brown, and hydrogen is evolved. Dissolve the re- 
sulting mass in water, and add hydrochloric acid in excess ; a 
copious deposit of salicic acid in fine needles occurs. This 
