230 THE AMERICAN MONTHLY [October, 



Prof. Kellicott briefly described a new collecting net, designed by 

 Prof. C. S. Fellows, of Minneapolis. 



The third paper, by Dr. H. N. Lyon, on " Notes of the Histology 

 of Attacuscecrofiia" was read by title only. 



Dr. George E. Blackham presented a paper on " Measurements of 

 the Amplifying Power of Objectives and Oculars in the Compound 

 Microscope," and with its discussion the forenoon session closed. 



THURSDAY AFTERNOON. WORKING SESSION. 



The afternoon session was devoted to the demonstration of practical 

 microscopic work, as follows : 



By L. D. Mcintosh, M: D. : Use of Solar Microscope and Stereopti- 

 con Combination. Among the objects projected on the screen were 

 histological sections from cat, including the intestine, brain, liver, and 

 kidney, larva of mosquito, section of human tooth showing dentine 

 and bone, section of human embryo foot showing ossification, Rinn- 

 bock's slides of arranged diatoms (published in the November number 

 of this Journal, vol. ix, 188S, facing page 199), lightning flashes, blood 

 corpuscles, bacteria, etc. 



By R. H. Ward, M. D., F. R. M. S. : Methods of Micrometry. 



Bv George W. Rafter : Use of Professional Photo-micrograph ic 

 Camera, and an improved method of making a microscopical examin- 

 ation of water. 



By A. M. Ewing, M. D. : The Working of a New Ether-freezing 

 Microtome, showing the freezing of a section of cancer. The micro- 

 tome exhibited by Mr. Ewing is a modification of that invented by 

 Mr. Wingrave, of London. By its comparative simplicity and cheap- 

 ness it possesses many advantages over the more expensive freezing 

 microtomes. 



By A. C. Chester, M. D. : Working of a Machine for Making Tin 

 Cells used in exhibitor's method of dry mounting. 



By George A. Bausch : General Construction of the Microscope. 



By Prof. J. D. Hyatt: Methods of Cutting Rock Sections. 



By R. R. Lansing, M. D., and R. N. Lansing, M. D. : Paraffine 

 Method of Imbedding ; Section Cutting and Mounting ; Mounting 

 Bacillus tuberculosis in balsam. 



By George E. Blackham, M. D., F. R. M. S. : Determination of the 

 angular aperture and working distance of objectives. 



By Edward S. Nott : Method of cleaning and mounting diatoms. 



By Roswell Park, M. D., and W. H. Bergtold, M. D. : Preparation 

 of culture media ; cultivation of bacteria ; making Esmarch's tubes. 

 Their exhibit of 7 3 tubes, cultures of bacillus of anthrax, Asiatic 

 cholera, scarlet fever, swine plague, bacillus typhoid fever, chicken 

 cholera, and many other well known diseases of man, the lower ani- 

 mals, and plants, was one of the principal features of the working 

 session. A glass jar was shown which contained the bacillus of water, 

 yeast, etc., growing on sterilized pieces of potato, bread, etc. Speci- 

 mens of red, black, violet, etc., from water were also shown. The 

 method of photographing microscopic objects by electric light proved 

 highly interesting, a miniature incandescent light being used. 



By Lucien Howe, M. D. : Preparation of nutrient gelatine for bac- 

 teria ; culture of bacteria taken from the eye ; staining of bacteria, 

 The doctor described the various stages of preparing gelatine for the 



