1892.] THE MICEOSCOPE. 197 



Bv Prof. D. S. Kellicott : "A Crustaceous Parasite of the 

 ^ Miller's-Thumb.'." 



By Dr. R. G. Nunn, " Scavengers of the blood." 



Bv Mr. G. W. Rafter, '• Microscopical Examination of Potable 

 Water." 



By Dr. A. Clifford Mercer. " Photomicrographs and Photomi- 

 crographical Apparatus." 



By Prof. M. D. Ewell, •' The Concave Mirror," -^ The Micro- 

 scopic Identification of Ink — A Metrical Examination of i.ooo 

 Signatures of the Same Person." 



By Dr. ]M. L. Holbrook. *' Structure of Red Blood Corpuscles 

 in Man." 



By Mr. Clark Bell. " Blood and Blood Stains." 



By Dr. Thos. D. Briscoe, '• The Wenham Binocular — can it 

 be made adjustable to a variable tube length ?'' 



By W. N. Preston, " On a New Mounting Table, and a Practi- 

 cal Drying Oven ?" 



By James H. Logan, "Precious Stones as Microscopic Ob- 

 jectives." 



The society met in Rochester eight years ago, and though its 

 growth has been very large since then, a large proportion of the 

 delegates seein to have pleasant recollections of their former visit. 



The meeting was an unqualified success and it is to be hoped 

 that the sixteenth annual meeting, which is to be held at Chicago 

 in August, 1S93, w^ill prove to be an attraction for a still larger 

 number of the devotees of the science of microscopy. 



^DEPARTMENT 



QUERIES AND ANSWERS. 



Questions of ail sorts relating to microscopy will be received by the publisher and re/erred 

 to Dr. S. G. Shanks, of Albany , N. Y.,zvhose replies 7vill be given in this department. Each 

 question is numbered for future reference. 



67. Houc is a polar iscope used, and where 7?iay I Jind a good 

 descriptio7i ? 



A polari scope consists of two similarly prepared prisms of 

 Iceland spar. One of them is placed closely beneath the object, 

 and is called the polarizer ; the other one, called the analyzer. 



