eine ance PROCEEDINGS OF SOCIETIES. 179 
AmeEricAN AcADEMY oF NaturaL ScrIENCES. 
Exhibition of the Biological and Microscopical Section. 
The Biological and Microscopical Section of the Academy of Natu- 
ral Sciences, whose First Annual Conversazione was so highly suc- 
cessful and gratifying to all concerned, has established a still further 
claim upon the medical men of Philadelphia to promote its objects, by 
entertaining their guests, the members of the State Medical Society, 
at its late meeting in this city, with an exhibition of microscopes and 
microscopic specimens, at the Hall of the College of Physicians, on 
Friday evening, the 10th of June. As this reception was especially 
intended for professional men, the class of objects displayed was quite 
different from the majority of those shown at the conversazione, in- 
cluding many illustrations in pathological anatomy and histology, of 
course chiefly interesting to physicians; and no effort being made to 
illustrate the history of the microscopes, only about two-thirds as 
many instruments, numbering about forty-five in all, each, however, 
in efficient working condition, were collected from the members and 
arranged upon the tables. Among the many beautiful and instructive 
specimens displayed, the Director of the Section, Dr. 8. Weir Mitchell, 
had on exhibition some very elegant preparations of teeth, bone, &c., 
mounted by Prof. Christopher Johnson, of Baltimore, and also a fine 
collection of blood-corpuscles from different animals. Dr. William 
Pepper, Vice-Director, further illustrated the subject by a series of 
blood-crystals of remarkable beauty. The wonderful amceboid move- 
ment, lately so famous in connection with both Cohnheim’s discovery 
of the origin of pus and Huxley’s great lecture “ On Protoplasm,” was 
well shown by Dr. J. G. Richardson, the Secretary, with a power of 
1300 diameters ; while the Corresponding Secretary, Prof. McQuillen, 
illustrated various departments of dental anatomy and physiology by 
magnificent sections of teeth of man and animals (showing among 
other points the inter-globular spaces), and of bone exhibiting the 
lacune and canaliculi. He likewise displayed very interesting speci- 
mens of human muscle infested with Trichina spiralis, from fatal cases 
of Trichiniasis ; also the infecting swine’s flesh. Prof. James Tyson 
had on exhibition a complete series of urinary deposits, which attracted 
much attention, and were among the most instructive objects presented. 
Dr. Wm. F. Norris contributed some exquisite specimens of nerves in 
the cornea, and capillaries showing their parietal nuclei—respectively 
gold and silver stainings—by the methods of Cohnheim and Reckling- 
hausen. Some very large sections of brain, kidney, &c., were displayed 
by Dr. W. W. Keen, who also showed sundry fine illustrations of 
nerve structure. Dr. W. B. Corbitt exhibited a very valuable series 
of specimens of various malignant and other tumours, collected in Ger- 
many, and many of them classified under the supervision of the great 
pathologist, Prof. Rokitansky. 
Mr. Walmsley (of the well-known firm of opticians, J. W. Queen 
and Co.) and Mr. T. W. Starr each contributed a number of the beau- 
tifully-mounted preparations for which they are so justly celebrated. 
