78 The West American Sczentist. 
in an opposite direction. The tube and occupant are highly 
transparent and viewed by dark ground illumination never fails 
to excite astonishment and wonder at the sagacity displayed by 
nature in protecting these minute organisms from their enemies 
and furnishing them with such elaborate means for obtaining their 
subsistence. Mr. Breckenfeld also exhibited a slide of A*cidium 
or ‘“‘cluster-cup fungus’’ found infesting the scanty vegetation on 
Signal Peak, Yosemite Valley, some seven thousand feet above 
sea level. 
Dr. E. G. Clark exhibited some interesting slides of Cinnabar 
ore in Chalcedony, showing {ree mercury, a rare thing in the 
natural state. The gentleman also showed a beautiful mounting 
of chrystallized gold, displaying the peculiar fern-leaf disposition 
of the chrystals produced by the galvanic current. 
The most notable feature of the evening was the exhibition by 
Charles C. Riedy of his collection of old and rare works of the 
early writers on microscopy. To the student and ali interested 
in micrographical literature this was an opportunity seldom 
offered to examine many volumes published by the pioneers in 
this branch of science, that are now very scarce. Mr. Riedy is 
devoted to the study of the Infusoria, and to facilitate his inquiries 
in that direction the present collection has been slowly accumu- 
lated, though not without great difficulty and perseverance, many 
of his orders for special works having been several years in the 
hands of European book-dealers before they were obtained. The 
different volumes cover the entire field of microscopical research 
from its very beginning, and contain a complete resume of the 
evolution of optical science, together with the progress of me- 
chanics as applied to the microscope. Many of the editions, in 
fact a majority of them, contain a high grade of illustrations con- 
sidering the date when they were executed, while some are em- 
bellished with fine-lined copper-plate engraving that wouid do 
credit to our own day. The oldest publications, belonging to 
the fifteenth and sixteenth centuries, are all bound in heavy parch- 
ment, and mostly written in the scholarly language of the time— 
Latin. The printing is remarkably good and legible, there being 
no perceptible fading of ink or paper. The authors represented 
were Adams, Baker, Baster, Bonanni, Descartes, Ellis, Eichhorn, 
Gleichen, Gotze, Grew, Hill, Hooke, Joblot, Ledermulier, Leeu- 
wenhoek, Martin, Needham, Power, Redi, Schaffer, Glapber, 
Smith, Spallanzani, Schott. Swammerdam, Trembley. Notable 
among these are Decartes’ works, with numerous wood-cuts, 
small quarto, Amsterdam, 1650. This work contains an illus- 
tration of Descartes’ gigantic microscope eight feet high. 
In the collection is Powers’ ‘‘Experimental Philosophy,in three 
books, containing new experiments, microscopical, mercurial, 
magnetical.’’ London, 1664. This last work is the earliest vol- 
ume on the microscope in the English language. 
Before adjourning a unanimous vote of thanks was tendered 
jpapel 
