1881. ] Scientific News. 347 
the first to use this material, has many thousands. The varnish 
to be used is what is called the “pale copal,” and its consistency 
ought to be that of oil. It is much pleasanter to use than Canada 
balsam, does not make bubbles, and its refractive index is not 
very different from that of balsam, and does not interfere with 
the solution of diatom markings. I have of late made many prep- 
arations in copal, dispensing with the cover-glass altogether. 
The drop of copal is placed on the diatoms and heated lightly 
over the spirit-lamp. It soon takes the consistency of amber, 
and is hard enough to sustain wiping and brushing with a soft 
brush with impunity—S¥ulien Deby, C. E., from the Fournal of 
Vi 
the Queckett Microscopical Club. 
IMporRTANCE oF STATING MAGNIFYING Power usED.—Mr. F. J. 
George very properly protests, in Science Gossip, against the vague 
and ambiguous phraseology used in connection with the magnified 
sketches of microscopic objects. Drawings which are lettered 
“highly magnified,” “much enlarged,” etc., are rendered un- 
scientific and absurd by the very words thus used to explain them. 
It would be-more rational, more instructive, and more satisfactory 
to every scientific reader, if such vague statements were replaced, 
in every possible instance, by a memorandum of the number of 
Porcine by which the drawing surpasses the size of the natural 
object. 
Co.umsus, Ou10, MaRcH 1, 1881. 
Epiror American NATURALIST : 
Dear Sir:—I am authorized by the president of the American 
Society of Microscopists to announce to its members, that the 
Executive Committee have decided by an almost unanimous vote, 
to accept the invitation received from Columbus, Ohio, and to 
call the next meeting of the society at that place, on Tuesday, 
August 9, 1981 (the week previous to the Cincinnati meeting of 
the American Association for the advancement of Science). 
Apert H. Turt.e, Secreary. 
:0: 
SCIENTIFIC NEWS. 
— From advanced sheets of the report of Professor W. K. 
Brooks, Director of the Chesapeake Zodlogical Laboratory of 
Johns Hopkins University, we learn that by the liberality of the 
Trustees he was enabled to spend a much longer period than 
hitherto at the seaside, and was provided with a more liberal out- 
fit, including a steam launch which was built for their use in the 
last spring, at Bristol, R. I., and has proved a very efficient auxil- 
lary. The necessary books, dredges and other instruments were 
also provided by the University. In addition to the opportunities 
afforded to three of the members of their own academic stall, 
three other gentlemen, devoted to the study of zoology, were 
