THE MICROSCOPE. 149 
curious things, then, and not till then, shall we hear the pens arising ~ 
from the throats of a never-credulous minority. We cannot, there- 
fore, publish further communications on this subject unless accom- 
panied with mathematical or other exact demonstrations proving the 
physical practicability of such feats. 
WE publish with this issue a portrait of our lamented friend, 
Mr. Henry Mills, which should have accompanied the obituary notice 
by Prof. Kellicott in our March issue. Mr. Mills’ death is a loss to 
the scientific world which will not soon be filled. 
MICROSCOPY.* 
Kuitscuirzky on THE Eacs or Ascons.t—In studying the 
conditions of impregnation in the ascon’s megalocephala, Kult- 
schitzky employed Van Beneden’s acetic acid-alcohol, p. e., as a 
killing and hardening agent. He also found that 3 parts ether 
and 1 part absolute alcohol, with acetic acid, or the acid-ether, 
diluted with one-third distilled water, gave excellent results. For. 
staining, acetic acid-carmine was generally employed, although Bis- 
marck-brown and malachite-green (Van Beneden’s), as well as 
aurantia and an alcoholic solution of gentian-violet were occasionally 
employed, but were found of little service, Although most observ- 
ers of the eggs of a megalocephala have mounted their specimens 
in glycerine, Kultschitzky found that as good or better results were 
obtained when balsam was used. He gives the method of procedure. 
The stained preparation is dehydrated in acetic acid, and then placed 
in a mixture of acetic acid and balsam. The section thus treated 
shows up well, but in time becomes darkened. To avoid this, the 
section is dehydrated in equal parts of alcohol and acetic acid, 
cleaned in creosote, and inclosed in creosote-balsam. Preparations 
thus treated are permanent. . 
Mayer’s Atpumen Fixarive.—Mr. J. Nelson finds{ that this 
fixative is absolutely reliable. One cannot obtain neat results with 
this, he says, except by means of a very even and thin film, to secure 
which proceed as follows: A small drop of fixative is spread on the 
slide with the ball of the index finger. Excess of fixative is 
* Under this heading will be included descriptions of New Instruments. Micro- 
scopical Manipulations, Stains and Re-agents, Photomicrography, etc. 
+ Arch. f. mikr. Anat., Bd. XXXI.—H. 4.—1888, p. 570. 
t American Naturalist, July, 1888, p. 664. 
