THE AMERICAN 



MONTHLY 



MICROSCOPICAL JOURNAL. 



Vol. XI. JANUARY, 1890. No. 1. 



All coittmunications for this Journal, whether relating to business or to editorial 

 matters, and all books, pamphlets, exchanges, etc., should be addressed to Ameri- 

 can Monthly Microscopical Journal, Box 6jo, Washingtori, D. C. 



European subscriptio7ts 7nay be sent directly to the above address accompanied 

 by International Postal Order for $i.i^ per annum, or they may be sent to Messrs. 

 Triibner &^ Co., 57 Ludgate Hill, Lojtdon, or to Mr. W. P. Collins, i^y Great 

 Portland street, London, acco?npanied by the yearly price of five shillings. 



An Easily Constructed Hot-Stage. 



By ROBERT W. SMILEY, 



WASHINGTON, D. C. 



A very simple and convenient hot-stage w^as exhibited by Dr. Robert 

 Reyburn at a recent meeting of the Washington Microscopical Society. 

 This form is adapted from the more complicated and expensive forms 

 used by microscopists, and is especially useful from the fact that it can 

 be made at a trifling cost by any one possessing a little mechanical skill. 

 In the frontispiece, figure 5, A represents the wooden block or stage, 

 vs^hich is fastened upon the brass stage of the microscope. A space is 

 cut from the upper surface of this block, as shown by C, into which is 

 fitted a piece of copper plate (B, B', B"). A round hole is also cut at 

 F, the opening of the brass stage, to allow illumination of the object to 

 be examined. The slide is placed on the copper bed with its ends rest- 

 ing at B' and B", as indicated by the dotted lines. The heat is applied 

 by a spirit lamp at the end (L) of the copper plate (B) which gradually 

 transmits the heat by conduction to the slide. The temperature is reg- 

 istered by the thermometer (E), which is screwed fast to the copper 

 plate. 



The importance of the use of a hot-stage in the examination of many 

 preparations is obvious. It is often desirable to keep objects at a given 

 temperature or to raise them above the surrounding atmosphere in 

 order that the effect of heat upon reagents and upon the vitality of living 

 micro-organisms may be obsei*ved. This form will be found to answer 

 the purpose admirably for nearly all occasions that may demand the 

 use of a hot-stage. 



Explanation of Plate. 



Fig. I. Hamilton's slide box. Fig. 4. Bryan's mounting clips. 



Fig. 2. Hamilton's slide tray. Fig. 5. An easily constructed hot-stage. 



Fig. 3. Pillsbury's reagent block. 



Copyright, 1890, by C. W. Smiley. 



