1891.] MICKOSCOPICAL JOUllNAL. 239 



which many additional facts and theories were evolved, and before ad- 

 journment a unanimous vote of thanks was tendered the Doctor. 



Sept. j6, J8gi. — A public exhibition and reception to invited guests 

 was given by the San Francisco Microscopical Society, which proved 

 very interesting and instructive. The Exhibition Committee had pro- 

 vided four large tables, on which were placed some fifteen microscopes, 

 and objects of rare beauty were displayed. 



The list of exhibits was so lengthy that it is not possible to speak of 

 all, but the following were particularly attractive : R. H. Freund had 

 a variety of bacteria, some from the laboratory of Dr. Koch, Berlin ; 

 Henry C. Hyde had a most interesting collection of diatoms, including 

 a number of genus slides, showing one hundred or more different 

 species on one slide. L. M. King showed some interesting living or- 

 ganisms, typical representatives of pond life. William E. Loy ex- 

 hibited a number of vegetable sections, stained and double stained. 

 George O. Mitchell exhibited specimens of marine zoology, the most 

 interesting being embryo snails in the ova in motion. Those who 

 watched this slide for a few moments were rewarded by seeing the 

 yovmg fry escape from their gelatinous envelope, so rapid were the 

 changes. Charles C. Riedy showed the secondary markings on dia- 

 toms under a one-twentieth immersion objective, and the human vol- 

 untary muscle under a one-sixth apochromatic, E. W. Runyon showed 

 a variety of objects with polarized light, and S. E. Taylor some beauti- 

 ful opaque slides. 



The Society intends to give these receptions at regular intervals in 

 the future, and it promises very satisfactory results. 



NOTICES OF BOOKS. 



Manipulation of the Microscope. By Edward Bausch. Bausch & 

 Lomb Publishing Co., Rochester, N. Y. i2mo., 127 pp. 

 This little book was written five years ago by Mr. Bausch and gives 

 in simple language the fundamental principles of the instrument and 

 the best method of technique. The demand for the work has been so 

 great that a second edition has been issued, in which the author has 

 enlarged on some subjects and rewritten others so that they will con- 

 form to the improvements of the present day. The intended purchaser 

 of a microscope will here find much valuable information relative to 

 the selection of his instrument. 



Special Catalog fiber Apparate fiir Mikrophotographie. Carl 



Zeiss. Jena. 



This catalogue should rank rather as a work of art than as an ad- 

 vertising publication. Throughout, the illustrations are elegant photo- 

 grapic prints. We have seen nothing to excel the photo-micrographs 

 of test diatoms. 



The Coming Reaction in Favor of Tuberculin. — Under the 

 above title Dr. Karl von Ruck has an able article m the Weekly JA'<//- 

 ca/ 7?ez'/Vw for August 22, 1S91. The author stands squarely by the 



