50 REPORT—1862. 
face of coagulated albumen. Boiling water in abundance was now poured over the 
paper, after which it was carefully dried. The photographic print thus produced, in 
consequence of the greasy ink upon the positive portions of the work, was capable of 
being transferred to stone by the printer, by the well-known mechanical process ; and 
from stones thus prepared, impressions could be pulled in the lithographic press. 
Numerous specimens were exhibited to the Section. 
On the Manufacture of Hydrocarbon Oils, Paraffin, Sc., from Peat. 
By B. H. Pav, Ph.D, 
The author described the results that had been obtained at some works lately 
erected under his direction in the island of Lewis, N.B. The peat of that locality 
was described as a peculiarly rich bituminous variety of mountain peat, yielding 
from five to ten gallons of refined oils and paraffin from the ton, The results ob- 
tained at these works were contrasted with those obtained at the works of the Irish 
Peat Company some years ago, where the produce of oil was not more than two 
gallons from the ton of peat. This difference in the produce was ascribed, in a great 
degree, to the improper mode of working adopted at the Irish works. One of the 
most important points dwelt upon was the necessity of regarding the hydrocarbon 
oils and paraffin as the only products that would afford a profit in working peat; 
and the failure of the Irish works was attributed to the attempt to obtain other pro- 
ducts which could only be regarded as waste, and not worth working, unless the 
oils and paraffin were obtainable in a remunerative amount from the peat. 
On the Decay and Preservation of Stone employed in Building. 
By B. H, Pavz, Ph.D. 
The causes and nature of the decay of building-stone were described as being 
both chemical and mechanical, and varying according to the nature of the stone an 
the conditions to which it was exposed. The various methods which have been 
proposed for the preservation of stone from decay were described in detail; the 
author considering, from a chemical point of view, that none of them presented any 
probability of success in effecting the desired result, and that the discovery of an 
efficient and practicable means of preventing the decay of stone, especially in towns, 
still remains to be made, 
On the Artificial Formation of Populine, and on a new Class of Organie 
Compounds. By T. L. Pureson, M.B., Ph.D., F.CS. Fe. 
The interesting substance populine was extracted in 1830 by Braconnot from 
the mother-liquors which had deposited salicine when the latter was obtained from 
the leaves and the bark of the pop'ar tree (Populus tremula). It was submitted 
to an important series of experiments by Piria in 1852, who found, among other 
interesting facts, that, in a variety of circumstances, populine split up into benzoic 
acid and salicine :— 
Co H22 ore + 9 HO = Cu He 0’, HO + O26 H}8 O4, 
Populine. Benzoic acid, Salicine. 
It occurred to me that salicine and benzoic acid might be combined so as to 
reproduce pee And this I find to be the case: when equal equivalents of 
salicine and benzoic acid are dissolved in alcohol and the liquid evaporated tc about 
half its bulk, magnificent acicular crystals of populine are obtained, some of which 
in my experiments measured nearly an inch in length. For every 100 parts of 
salicine must be taken 43 parts of benzoic acid. Or fo: 100 parts of salicine, 53-5 
parts of benzoate of soda and a sufficient quantity of diluted sulphuric acid to satu- 
rate the soda of the benzoate ; alcohol is then added, and the sulphate of soda sepa- 
ee i filtration. By evaporating the solution long needles of populine are 
obtained :— 
Cu Hé Ot + O76 Hs Ou = (Ox H owe + 2 HO). 
Benzoic acid. Salicine. Crystallized populine. 
The properties of the populine thus formed are precisely those of the natural 
