REPORTS OF SOCIETIES 
89 
arranged by Mr. F. H. Collins. The President read some very pleasant 
letters from some Sociologists at a distance who are interested in the 
section, and Mr. J. O. W. Barratt repeated (by special request) his 
illustration of the material changes occurring during the life of an 
Amoeba. The study of Mr. Spencer’s “ Principles of Biology ” was then 
proceeded with, Chapter 7 of Part II. being introduced by Mr. W. W. 
Collins, and this was followed by a discussion, in which the President, 
Messrs. C. H. Allison, W. Greatheed, S. D. Williams, and the Secretary 
took part. 
BIRMINGHAM AND MIDLAND INSTITUTE SCIENTIFIC 
SOCIETY.—Feb. 6.—Mr. C. J. Watson gave an interesting description 
of a trip “Round Snowdon with a Camera,” and exhibited a large 
number of slides, many of them showing the effects of the Glacial 
Period.—On Feb. 13 Mr. E. B. Marten, C.E., of Stourbridge, showed 
some beautiful apparatus made by Mr. Wm. Grove, after the designs 
of Mr. Stroh, of London, to illustrate the action of vibrating discs or 
drums upon one another, causing attraction when their movements or 
vibrations are alike and repulsion when they are unlike. Also, when 
a light metal disc was suspended between two vibrating drums it 
arranged itself in the line of their axes when the vibrations were alike, 
and at right angles to the axes when unlike. The same kind of disc 
was suspended between two electro magnets when it showed move¬ 
ments very analogous, but in reverse order, as it was at right angles to 
axes of the magnets when they were both similar poles and in the 
line of the axes when the poles were contrary. It was explained that 
this had been noted by Dr. C. A. Bjerkner, of Christiania, in 1856, and 
illustrated by beautiful apparatus for showing the effects upon bodies 
suspended in water at the Paris Electrical Exhibition. Similar effects 
were shown with a cardboard vane poised like a weather-cock, and 
also with two discs connected like a pair of spectacles and suspended 
by a thread. The action was explained by showing that when the 
discs approached the air between was driven out sideways, and on 
parting a partial vacuum was formed between them, and the air at the 
back of the disc on the vane pushed it forward. If a rim was put 
round the vibrated disc the action was the reverse, and the vane was 
repelled. Some other curious effects of atmospheric impact were 
illustrated with a disc suspended before a hole in a box with an elastic 
side, which approached when the beating of the side caused a puff of 
air and a reaction. The same was shown by a disc held up by a current 
of air from a hole in the centre of another disc; and again by the falling 
of some cardboard figures towards a vibrated disc. Two large diagrams 
made for that meeting explained the work of Dr. Bjerkner and Mr. Stroh 
respectively. Feb. 20th.—Mr. W. W. Staveley read a paper on “Frac¬ 
tional Distillation.” After briefly alluding to the history of the subject, 
he dealt with the various forms of apparatus used in the laboratory, 
and the industrial apparatus used on an immense scale in the 
manufacture of alcohol, benzene, etc., showing, by means of diagrams, 
the gradual advance from the primitive cucurbit or alembic of the old 
alchemists to the complicated apparatus of the present day. He next 
gave comparative results obtained with each form of apparatus, and 
concluded by presenting in a succinct form all that is at present 
known relating to the theory of distillation. 
BIRMINGHAM MICBOSCOPISTS’ AND NATURALISTS’ 
UNION.— January 21st, opening night at new rooms.—Mr. Darley 
exhibited a collection of moths, including among many others large 
