158 
PBOCEEDINGS OF SOCIETIES. 
Adelaide Microscope Club, South Australia.* 
The monthly meeting of the club was held on April 30. Dr. 
Whittell presided. 
Mr. Francis showed some glasses he had succeeded in ruling with 
fine lines to show the effect of diffraction. 
The Chairman said the subject for study that evening was " The 
Animal and Vegetable Parasites of the Human Body," and after 
giving a general summary of the facts known respecting these bodies, 
proceeded to show several varieties of them under the microscope. In 
referring to the Microsjporon furfur, he noticed the statement of some 
dermatologists that it required considerable skill to demonstrate it. 
He had not found this to be so. If some of the scrapings from a skin 
affected by it be soaked in Beale's staining fluid for a few hours, the 
sporules will be found to be coloured, while the dead epithelial scales 
will be scarcely touched. In referring to Hydatids, the Chairman 
showed a slide containing a minute portion of the contents of a cyst 
in the hepatic region. There were booklets of the echinococcus and 
thousands of minute ovoid bodies, which Dr. Cobbold, of London (to 
whom similar slides had been sent), had pronounced to be protospermial 
bodies, although differing somewhat from any he had before met with. 
The patient from whom they were obtained by tapping had ultimately 
made a good recovery. 
The Kev. Dr. Bleasdale, a distinguished visitor from Victoria, 
called attention to the effect of oblique light obtained by removing the 
mirror of the microscope and viewing an object illumined by the 
direct light of a candle or lamp placed to the right or left of the ob- 
server. 
A committee was appointed to arrange for the holding of a 
conversazione. 
Microscopical Section of the Academy of Natural Sciences 
OF Philadelphia. 
February 1, 1875.— Director W. S. W. Euschenberger, M.D., in 
the chair. 
Dr. J. Cheston Morris, chairman of the committee appointed to 
examine optically the ^^th. and g^th objectives displayed at the late 
Exhibition of the Section, made a report, which was referred to a 
committee, and of which the following is an abstract : 
The lenses submitted for examination were a -^th, j\th, and ^Qth. 
made by Tolles, all immersion, a ^^th immersion by Wales, and a 
Jjjth, dry, made by Powell and Lealand. The points which we con- 
sidered it requisite for us to examine were, 1st, flatness and clearness 
of field ; 2rKl, definition ; 3rd, penetration ; 4th, resolution ; 5th, angle 
of aperture ; 6th, achromatism ; 7th, amplification ; 8th, working focus. 
Penetration or depthing is the property by which a lens shows us with 
tolerable distinctness objects or structures lying just within or beyond 
the best focal point or plane, and is of the greatest importance in 
* Report supplied by Dr. Whittell, Adelaide. ^ 
