ur. TIIK AMERICAN MONTHLY [May, 



(j^) Titles. — I slu)ulii like to sec a l)il)lio«jraphy olthc oi i<;iii;il 

 articles tlial appear in microscopical tecluiiqiie ami in the various 

 sciences in which the microscope is useil. A complete list ot" 

 hooks, papers, etc., etc., is »:[oocl. I have a card catalogue of all 

 vou pnhlisheil alreatly. For indexing the periodicals, etc.. the 

 si/.e wf' card that you suggest is gooil. hut lor indexing articles, 

 some preter other sizes. .\ printed lahel is. of course, much bet- 

 ter than a written one. \' . A. MoouK. 



\V.\siiiN».rt)N. March 2J. 



(24) Titles. — The sciieme is admirahle. I wish you would 

 include the price ami number of illustrations. These facts are of 

 value to one selecting hooks to purchase. .\. 1'. W'kankk. 



Jackson, March 24. 



(25) Titles. I was struck with this plan. It must he very 

 useful. I would suggest, however, (i) larger type, (2) names of 

 authors in holder type. (3) ailditional space between tlic items. 

 The small tv|)e mav be trying to the eyes of middle-aged people. 



J. P. TlIO.MI'.SON. 

 PORTI..\ND. March 22. 



(26) Titles. — I have used such a scheme as you propose for 

 several years and vour lists would have saved me a good deal of 

 trouble. I find a tew new items in yoiu" February list. I will 

 help on this work as soon as I get settled. ]. M. .Stekdman. 



AlBUKN. Ai-A.. March JO. 



(27) Titles. — The scheme I think a good one. I should ad- 

 vise thi^t each title be printed twice, so that two carils can be 

 made — one tor authors and one for sul^jects. I have used such an 

 one for a long time ; every article worth keeping track of is en- 

 tered. Leave space between tlic titles so as to make it easier to 

 cut and paste them. H. L. Osborn. 



St. Paul, Minx.. March 20. 



(2S) Titles. — I do not see the utility of a mere list of books, 

 as but few of us have so extensive a librarv as to render it neces 

 sarv to catalogue them, but a list of all microscopical books, giv- 

 ing a short review of the contents and the prices, would be a 

 consideration and assist intending purchasers. .S. G. Shanks. 



Albany, N. V., March 27. 



Ml( H(^S(OIM( AL .VFM».\H.\riS. 



Micrometer Calipers. — This instrument is convenient for 

 measuring tlic thickness of cover-glasses. That it was not 

 mentioned by Prof. S. H . Gage in his recent volume was purely an 

 oversight and not a lack of appreciation nor of knowledge. Prof. 

 Gage writes us that when he tried the calipers in comparison with 

 cover-glass measurers the results obtained on the same glasses 



