Entomological, Section, Octouer 10th— First; even- 
incT meeting this session. Mr. S. B >rton, prpsident, occnnipid 
the chair, and there was a good attendance of members. After 
the reading of the minutes of the excursion moetings, Mr. 
W. L. Carpenter mentioned 'the desirability of noting the 
occorrence of every species, however common, with q viewr 
to ultimate publication in the Society's work on the Natnral 
Historv of the district. The secretary, Mr. Hardinef, called 
upon members to furnish papers for the evpning nfieetintra, 
and by way of setting the examole, read a short note on the 
occnrrpnce of a species of Eupithecia, new to th\<* district". 
In 1862 be had captured a worn snecim<^n of this e'^nn^, 
with which hf» was unacquainted, and could not identifv its 
»^peciefl; in 1863 and 1864, he had searched for it unsncf'oaQ- 
fullr, but two specimens were shown to the section in 1864, 
^hich he believed to be of the same specie'^ as his capture. 
These bad been taken near London, by Dr. Knaerffs, and 
named E. lariceata. In Jane of this vear, between the 6th and 
20th, Mr. Harding had taken at Brocklev a few specimens, 
on or near larch trees, on which the larvae fed. He exhibited 
these, and also a fine specimen of Acherontia Atropos, or 
death's head moth, bred this year. Mr. A, E. Hadd showed 
Lycasna Lnreyi and L. Adonis, a foreign species. Mr. Bolt 
brouebt a fine series of insects, which might be captured in 
ivy du'-'ng the present rnonth, including Das^carapa rubi- 
ginea. Xanthia Aurago, Xylina semibrunnea, X. petrificata, 
and Heliothis armigera, rarely found, a collection which was 
the result of several years' work. Mr. Jacques mentioned a 
remarkable instance of a white cabbage butterfly larva, 
which did not spin silk as a rule, climbing a smooth vertical 
sheet of glass by the aid of this excretion, produced for that 
purpose. 
Chemical AND Photographic Section, October 11th. 
— Dr. Heranath, F.R.S., president, in the chair. The secre- 
tary, Mr. Noble, stated that at the meeting summoned for 
September 13th, and then postponed to the 20th, so few mem- 
bers attended that no business wa-^ done. He was glad to see 
so large an attendance that evening, and hoped that as 
thirty gentlemen belonged to the section, as many as possible 
would make an effort to attend. The Rev. W. Whiting, M.A. 
then brought for vsrard some illustrations of the phenomena 
of polarised light, shown bv Goddard's new form of polaris- 
copp, made by Hierhley, of London. The light from an oxy- 
hvdrogen lime-light, enclosed in a lantern, fell upon a bundle 
of gla-«s plates at an angle of 56° 45', and, reflected thence in 
a poUrised condition, passed through the crystal, or other 
substance to be examined, then through several lenses, and 
finally through a Nicol's prism, two inches in length, called 
the analyser, after which it fell upon a white screen, where 
the phenomena were visible to a large audience, instead of 
only to one person at a time. In giving a brief explanation 
of the cause of the remarkable colours brought out, Mr. 
Whiting insisted strongly on the axiom that the index of 
refraction was the tangent of the polarising angle of any 
substance, and hence that the reflected and refracted ray 
were at right angles to each other. After sonae interesting 
experiments with tourmalines, some curious specimens of 
unannealed glass were submitted to the instrument, and very 
remarkable lines and bands rendered visible in it. Many 
sections of crystals were examined, showing the crosses, 
coloured rings, &c., characteristic of each, and which were 
invisible with ordinary light. S^rae of the most beautiful 
objects were designs in different thicknesses of selenice, 
which changed their colour during the rotation of the 
analyser — green fruit, for example, becoming apparently 
rine, and a chameleon changing its hue constantly, Mr. 
Whiting, who was assisted both in the experiments and 
explanation by the president, stated that, as far as one trial 
enabled him to jadge, the polarisation of light did not affect 
it^ actini^Ti or power of acting on chemical substances for 
photoarraphic purooses. 
