84 



THE AMEEICAN MONTHLY 



[May, 



Placing two slides back to back, so 

 that the growth should be on one 

 side only of a slide, I put them in the 

 pins in couples, and then strapping 

 over the hoops a piece of wood suffi- 

 cient to flood the whole, I put it in 

 the water, and left it long enough for 

 my purpose. As a result, I have a 

 number of slides in various stages of 

 growth, of schizomycetes, desmids, 

 algge, infusoria, etc., which I would 

 not part with for a great deal, surely 

 not at all if I could not dviplicate them. 

 F. T. Hazlewood. 



The Improved 'Investigator' 

 Stand. 



The Bausch & Lomb 

 Optical Co. have greatly 

 improved their ' investi- 

 gator' stand, and we give 

 this month an il- 

 lustration of the 

 instrument in its 

 present form. It 

 will be 

 seen that 

 changes 

 have been 

 made 

 in the 



mode of attaching mirror and sub- 

 stage, which now swing independent- 

 ly of each other on separate arms, 

 graduated to show the extent of angu- 

 lar movement. The position of the 

 body-rack has been changed, giving 

 a greater range of motion, and the 

 stand as a w^hole is improved in ap- 

 pearance, and seems eminently adap- 

 ted to the wants of a large class of 

 general microscopists. Finther par- 

 ticulars concerning this stand are 

 given in the supplementary catalogue 

 recently issued by the fii*m. 



We would call particular attention 

 to the artistic excellence of the wood- 

 cuts used by this company in 

 their catalogues. Some of 

 them are very superior, and 

 the one here given is admir- 

 able. 



Fig. 19. — Bausch & Lomb's ' Investigator,' improved. 



Mounting in Balsam in 

 Cells. 



BY R. P. H. DURKEK. 



The same or a similar 

 method of balsam mounting 

 in cells may have already been 

 worked out by others, but on 

 the assurance of several of 

 much greater experience than 

 myself, that they had never 

 seen anything of the kind, and 

 on their approval of what, so 

 far as I know, is entirely origi- 

 nal, I send you a specimen 

 and a short description of its 

 preparation for publication in 

 the Journal. Its prepara- 

 tion differs from others in that 

 there is no previous building 

 and drying of the cell. 



A curtain-ring, flattened by 

 pressure, is placed upon a 

 clean slide and the slide placed 

 on the hot table. Drop in 

 the centre a small portion of 

 balsam, enough to fill the cell, 

 and heat till the air-bubbles 

 rise and permit of breaking 

 with the needle, at the same 

 time gently moving the ring 

 about, and pressing it down to 



