210 Mons. R. Piria on the Combinations of Salicyle, 
and also more perfect means than we now possess of mea- 
suring the amount of the inductive action; all these circum- 
stances render the problem very complex. 
[To be continued.] 
XXXVIII. Researches of Mons. R. Piria on the Combina- 
tions of Salicyle^, 
Tf'VERY one who is at all acquainted with the gigantic 
strides made in organic chemistry since the discovery of 
the real nature of the oil of bitter almonds, and the develop- 
ment of the remarkable combinations of benzoyle, must have 
hailed with peculiar pleasure the discovery of an analogous 
series of compounds having for their base a compound radical 
termed spiroil, from its being present in the oil of the Spircea 
Ulmaria^ or meadow-sweet. This body was discovered by Ld- 
wig, who ascertained the volatile oil of the Spiraea to be really 
an hydracid, consisting of a compound radical analogous to ben- 
zoyl, combined with hydrogen. The researches of Lowig have 
been already presented to the English reader in the pages of 
the valuable Scientific Memoirs of Mr. R. Taylor. We have 
now the pleasure of laying before our scientific readers an 
account of a valuable series of researches of M. Piria on anew 
compound organic base, bearing considerable resemblance 
to benzoyl and spiroil, and promising, from this very resem- 
blance, to throw much light on the nature of the respective 
combinations of these curious bases. 
The active principle of the bark of different species of salix 
has been long known to chemists, and salicin is now an ordi- 
nary article of commerce, being employed in medicine -as a 
substitute for quinine, as a remedy in intermittent fever. 
Salicine was first obtained in a white crystallizable state, 
by M. Leroux, and has been submitted to ultimate analysis 
by MM. Jules Gay-Lussac and Pelouse. Piria has also 
analysed it, and its per centage composition was in three ex- 
periments found to be as follows : — 
Exp. 1. 
Carbon 55*68 
Hydrogen ..... 6*36 
Oxygen 37*96 
Exp. 2. Exp. 3. 
55*0^1? 55*54j 
6*39 6*43 
38*57 38*03 
100 100 100 
* For this account of M. Piria’s researches, the Editors arc obliged to 
Dr. Golding Bird. 
