^JoTial.^aTMmT NOTES AND MEMORANDA. 315 
screwed one or other of a series of brass rings K, having cemented on 
their surfaces a thin glass disc of suitable thickness. The ring with 
thin glass may be removed from either side of the compressorium to 
place the object in position, which it should just touch when replaced ; 
and as the whole of the compressing arrangement is contained in the 
thickness of the metal frame, both sides of the object can be examined 
with equal facility. 
The Belgian Academy's Prize. — Among the prizes proposed for 
the Concourse of 1870 by the Belgian Academy is one the subject of 
which may interest some of our readers. The subject (No. 4) is thus 
stated: "To make known the development of insects of one of the 
orders having complete metamorphoses, bearing especially on the 
least known phases of evolution." The value of the prize is 600 francs. 
Manuscripts should be sent in to the Secretary of the Academy at 
Brussels before the 1st of June, 1870. The author's name must not 
be attached to the MS., but must be given in a sealed envelope accom- 
panying the memoir. 
A New Micro-spectroscope, possessing special advantages, has, 
we hear, been devised by Mr. W. Crookes, F.E.S., and is made by 
Mr. Charles Collins. We have not yet examined the instrument, and 
we therefore reserve our opinion of its merits till we can speak with 
authority. 
Messrs. Powell and Lealand's New Condenser was exhibited at 
the last meeting of the Eoyal Microscopical Society, and certainly is 
a very excellent though simple piece of apparatus. It consists of a 
hemispherical lens by which the diverging rays of a lamp are thrown 
in a parallel bundle and in a nearly horizontal plane beneath the 
object under examination. 
The Lowest Form of Living Protoplasm. — A " Fellow " remarks 
that the Amoeba is not the lowest form of animal life, though so fre- 
quently selected as such. Professor Huxley's Bathybius will probably 
in future take its place. 
Desiccation of Eotifers. — A correspondent writes to ask us for 
information on this point. We trust that some of our readers will 
make a few experiments and give us the results. Some naturalists 
assert that rotifers may be placed on a glass slide in a drop of water 
and gradually dried by heat without destroying them, and that in 
this state they may be maintained for any length of time, a drop of 
water sufiicing to revive them. Others as decidedly deny it. It 
might very readily be tested. 
Does Boiling destroy Germs ?~This question cropped up in the 
course of the Pasteur and Pouchet controversy on Heterogeny, and it 
appeared that there are some germs that are not destroyed by boiling, 
but which require a temperature some degrees (10° or 12°, Ave believe) 
above boiling. This is another simple problem for microscopists. 
Spontaneous Generation. -— We are informed that one of the 
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