PROCEEDINGS OF SOCIETIES. 



101 



" usable " as an inch, &c. But to continue. In process of time a 

 great improvement was announced in the said J(r*li 5 and as I always 

 wish to keep up with the " march of improvement," I accordingly- 

 ordered one of the " last improved," which was extolled as having 

 an angle of 175° ! 



Well, I found it did " perform " beautifully upon all that it could 

 reach : but, alas ! I had the mortification to find that about half of my 

 extensive collection of Diatomacefe were thrown out of use, as far as 

 this tremendous 175° was concerned : and it became necessary to fall 

 back upon the old and more moderately angled glass. 



Consequently, all my high-power objects have long been labelled 

 Y^^th and U. y^*^ 5 *^® latter implying old sixteenth. 



Things were in this state when the new " aquatic nozzle " was 

 invented ; and on having one of them adapted to my new yV^li I ^^^ 

 the pleasure of finding that the new mode not only brought out the 

 diatoms with much more brilliancy, and also considerably greater am- 

 plification (converting a ^Lth into about aV^l^)' ^^^*' ^^^^ °^ ^^^' ^* ^^ 

 much elongates the focal distance, that all my 0. yV^li objects became 

 perfectly usable, and much better seen than formerly. 



Thinking the simple fact now stated may possibly be of use to 

 others who have " unusable " sixteenths, I have ventured to send you 

 this letter; and am, Sir, 



Yours very respectfully, 



Henry U. Janson. 



PROCEEDINGS OF SOCIETIES. 



Medical Microscopical Society. 



The fifth ordinary meeting of the above Society was held at the 

 Eoyal Westminster Ophthalmic Hospital on May 16th, at 8 p.m.; 

 Jabez Hogg, Esq., President, in the chair. 



The minutes of the last meeting having been read, and the names 

 of gentlemen proposed as members having been announced, Mr. Atkin- 

 son read a paper on " The Preparation of the Brain and Spinal Cord 

 for Microscopical Examination," which will be found in full at p. 27. 



In the discussion which followed, the President considered that 

 for staining, Beale's carmine solution diluted fourteen times with 

 water was strong enough, and preferred rosaniline and logwood for 

 staining. The use of spring-clips in mounting increased the chance of 

 air-bubbles. 



Mr. White thought bubbles might be avoided by using balsam 

 dissolved in chloroform. 



Dr. Pritchard agreed with Mr. White. Before dissolving the balsam 

 in chloroform he dried the former at a temperature of 200° Fahr. 



Mr. Paul was in the habit of placing his chromic acid specimens 

 in glycerine to render them still harder. 



Mr. Needham used the carmine solution reduced to one-fourth its 

 strength : it stained best after being made three weeks. 



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