PROCEEDINGS OF SOCIETIES. 
821 
very handsome work " On the Quinology of the East Indian Plan- 
tations," presented to the Society by the author, John Elliot Howard, 
Esq.. F.R.S., and a special vote of thanks was recorded. 
The President reminded the Fellows that they would hold a 
scientific meeting for the examination of objects, &c., on Nov. 8, and 
expressed a hope that there would be an effort made to render the 
occasion as interesting as possible. 
A paper by Dr. G. W. Royston-Pigott, " On a New Refracto- 
meter for Measuring the Refractive Index of Thin Plates of Glass, 
Tubes, &c.," was read by the President, and was illustrated by 
diagrams enlarged upon the black-board, and also by the exhibition of 
the instrument itself, specially lent for the occasion from the Loan 
Collection of Scientific Apparatus at South Kensington. 
The President thought the plan adopted by Dr. Pigott was very 
ingenious, and would in many cases prove to be very useful where no 
other means could be adopted, as, for example, in identifying the 
minerals seen in thin sections of rocks. He might mention that he 
had been lately studying the microscopical characters of various sand 
deposits, and had found amongst the grains a material which had 
a much higher refractive index than that of quartz. When mounted 
in Canada balsam, and illuminated by a spotted lens, pure quartz, 
owing to its very similar refractive index, was almost entirely lost 
to sight ; but he had found in some sand from the neighbourhood of 
Dunkeld grains of a substance which reflected brilliant light, owing to 
its much higher refractive index, and he thought it probable that this 
might prove to be corundum, which he believed had not hitherto been 
recognized as forming any part of our native sands. In such cases as 
this he thought the apparatus described by Dr. Pigott might be very 
useful. 
A vote of thanks to Dr. Pigott for his communication was unani- 
mously carried. 
A paper by the Rev. W. H. Dallinger, " On some Experiments 
with a Sterile Putrescible Fluid exposed in an Optically Pure Atmo- 
sphere, &c.," was read by Mr. Charles Stewart, who drew upon 
the black-board a sketch of the apparatus described and figured 
by the author, and explained the means which had been adopted 
in carrying on the experiments. (The paper will be found at 
p. 288.) 
The President, in proposing a vote of thanks to the author of the 
paper, felt sure that all present must greatly admire the industry of 
Mr. Dallinger, as well as the ingenious contrivance which he had 
described; and they would no doubt be interested in the curious 
results obtained. Having never himself made any experiments on 
these subjects, it would hardly become him to do more than call atten- 
tion to the importance of these investigations as bearing upon those 
questions of the relations between life and matter which had given 
rise to so much discussion of late. 
The thanks of the meeting were unanimously voted to the Rev. 
W. H. Dallinger for his paper. 
