oF 
THE MICROSCOPE. 25 
Man, being the servant and interpreter of nature, can do and 
understand so much, and so much only, as he has observed, in fact 
or in thought, of the course of nature. Beyond this he neither 
knows anything nor can do anything.—Bacon’s Novum Organum, 
Aphorism I.’ 
By dissolving Aurantia or Gentian violet in creosote, a staining 
and cleaning of the section is obtained at the same time.— 
Kultschitzky. 
Ar the recent meeting of the American Public Health Associa- 
tion, held in Milwaukee, Dr. Theobald Smith of Washington, was 
down for a paper on “The Relations of Bacteriology to the Discoy- 
ery and Prevention of Infectious Disease among Men and Animals.” 
Lirrett (November 17, 1888), reprints from the London Quar- 
terly Review an article on “Cruising and Dredging,” which will be 
found of interest to microscopists. 
Pror. H. M. Wuetptey calls attention in Meyer Bros,’ Druggist 
to the fact that the ordinary bleaching agents employed in micro- 
scopy will corrode the glass of the solid watch-glasses sold for micro- 
purposes. The action of these agents turns the glass opaque, and 
renders them unfit for use on the stage of the microscope, where 
they are often employed, with low power, in the examination of 
transparent bodies. 
Sipyey J. Trxpaty suggests, in Science Gossip, the scales from 
the red currant as a pleasing object under the polaroscope. The 
scales are obtained by scraping the tongue after eating this fruit. 
Tue Pry-Hote Camera.—A writer in Anthony’s Bulletin claims 
for the pin-hole camera that, by doing without a lens, weight and 
expense are saved. As wide an angle as the camera will admit of, 
say 120° on the horizon, may be taken, against 80° to 85° with a 
wide-angle lens; all objects, near and far, will be in equally good fo- 
cus; the size of the image may be suited to fit the plate, without 
changing one’s point of view; a view may be taken, if necessary, 
directly towards the sun, as there is no trouble from fogging caused 
by the sun illuminating the surface of the lenses. 
Tue Iowa assembly of the Agassiz Association held its fifth 
annual convention at Mount Pleasant, August 21 to 23. Dr. F. P. 
Peck, of the lowa State Hospital for the Insane, delivered an address 
on “Notes on the Anatomy of the Brain,” and other interesting 
proceedings occupied the attention of the chapters represented,—14 
in all. The next meeting will be held at Oskaloosa. 
