66 
M. Liturata, F. Piniaria, and T. Variata, being vevy abundant among 
fir trees. 
Among the species of Coleoptera taken, may be enumerated 
Leptura Melanura. 
Cryptocephalus lineola. 
Cocinella ocellata. 
" oblong-punctata. 
Cistela castanea. 
Phyllobius calcarotus, 
besides a large number of more abundant species. The captures were 
not altogether confined to Entomology, as Listera Nidus-avis was found 
growing at the foot of an oak tree, and two specimens of the viper were 
seen, one of which was disabled by a blow from a stick, and duly boxed to 
accompany the members back to Bristol. 
CHEMICAL AND PHOTOGRAPHIC SECTION. 
"Wednesday, June 13.— Mr. P. J. Worsley, F.C.S., President, 
in the chair. 
Mr. William James exhibited some negatives which had been inten- 
sified by a solution of persulphate of uranium, mixed with ferricyanide of 
potassium. They were of a crimson colour, and the increased intensity, 
which was well shown in the prints taken from them, was apparently due 
to an alteration merely in the condition of the deposit, and not to an 
addition to it, as was the case when most of the intensifiers in ordinary 
use were employed. On this account, this new preparation was considered 
preferable. 
Dr. W. B. Herapath gave an account of an examination of various 
precious stones with the micro-spectroscope, undertaken with the view of 
finding out whether by this means, imitation gems could be distinguished 
from real. Sapphires of a deep blue could be distinguished from the 
cobalt blue glass, but with pale blue stones there was no perceptible 
difference in the bands. It was very easy to decide between a garnet and 
red glass, the latter cutting off nearly all the spectrum beyond the orange, 
while the real gem produced three decided bands, two in the green, one in 
the yellow. Most yellow and orange stones gave no bands, nor did the 
emerald, nor the amethyst. The imitation of the spinel ruby was very 
successful, producing an absorption band in the green, as did also the gem 
itself, which was of a pale pink color. 
The gentleman who was to have read a paper on Pouncey's Carbon- 
printing process, having failed to keep his engagement, the Section shortly 
afterwards adjourned until the second Wednesday in September. 
