7<5 The West American Scientist. 



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 ^'Ecidium 

 or "cluster-cup fungus" found infesting the scanty vegetation on 

 Signal Peak, Yosemite Valley, some seven thousand ieet above 

 sea level. 



Dr. E. G. Clark exhibited some interesting slides of Cinnabar 

 ore in Chalcedony, showing free mercury, a rare thing in the 

 natural state. The gentleman also showed a beautiful mounting 

 of chrystallized gold, displaying the peculiar fern-leat 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 all interested 

 in microgi-aphical 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 seveial 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 would 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 ot 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, Easter, Bonanni, Descartes, Ellis, Eichhorn, 

 Gleichen, Gotze, Grew, Hill, Hooke, Joblot, Ledermuller, Leeu- 

 wenhoek, Martin, Needham, Pouer, Redi, Schaffer, Glabber, 

 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 



