*^08 The Microscope. 



Aside from the gifts of Mr. Durant and purchases, the collec- 

 tions have been enriched by generous friends. The first gift was 

 from Mr. G. W. Corthell, of Boston, of double stained plant sec- 

 tions. He also gave a demonstration of his methods of staining 

 and mounting. I'he society is further indebted to Mr, W. H. 

 Walmsley, of Philadelphia, for slides and photographs; to Mr. T. 

 D. King for slides of sections of pine needles, odontophores, etc. ; 

 to Dr. Thomas Taylor, of Washington, for specimens of crystals in 

 fats; to Mr. ^\. H. Griffith, F. R. M. S., and Vice-President of the 

 American Society of Microscopists, for a collection of slides of his 

 own mounting, and through him to Dr. Duffield, of Detroit, for fine 

 histological and pathological specimens, and to Mr. J. D. Walker, 

 F. R. M. S., of Utica, for a number of his unsurpassed diatom mounts. 

 Others have presented valuable slides in smaller number. The 

 Society has had more than 140 different members, many of whom 

 have purchased microscopes to continue their work after their college 

 days, and we start out on a new decade with fresh courage, believing 

 that the outcome has justified the novel experiment of a College 

 Society of this sort, composed largely of students. 



SAN FRANCISCO MICROSCOPICAL SOCIETY. 



A MEETING of this Society was held May 11, 1887, Presi- 

 -*• ^ dent Wickson occupying the chair. 



The Secretary' announced the receipt, fi'om Dr. Thomas Taylor, 

 Microscopist of the Department of Agriculture, Washington, D. C, 

 of the last annual report of that department, accompanied by a 

 number of colored plates, photo-engravings and photo-micrographs, 

 illustrating the crystallography of butter, and of other animal fats. 

 A great deal of work is now being done by Dr. Taylor in regard to 

 this important subject, and his investigations, thus far. show that 

 the fats of different animals differ in their ciystallization. For 

 example, if small quantities of butter, of lard and of beef-fat be 

 separately boiled and slowly cooled for twenty-four hours, the 

 resulting crystals will show very marked differences under the mic- 

 roscope. The normal butter crystal is large and globular, polarizes 

 brilliantly and shows a well-marked St. Andrew's cross. That of 

 lard shows a stellar form, while that of beef- fat has a foliated 

 appearance. In course of time, as the butter loses its freshness, the 

 globular crystals degenerate and gradually merge into peculiar 

 rosette-like forms. The different stages of the crystallization could 



