1881.] 



MICKOSCOPICAL JOUE^NAL. 



23 



(irowing-slides. 



Requiring the use of growing-slides 

 in the course of my observations, I 

 have obtained different ones, some 

 costing several dollars. All performed 

 well so far as they went, but the sup- 

 ply of water being so limited, it soon 

 became exhausted. Believing that I 

 have obviated the difficulty, I take 

 the opportunity of calling attention 

 to my new plan. I have drilled a 

 small hole near the margin of a con- 

 cave slide, or near the centre of a 

 plane one. Through this hole I put 

 a strand of cotton thread, with one 

 end in contact with the glass cover, 



Fig. G. — Microscope attached to a desk or another support, by the screw-holder. 

 The Turn-table can also be attached in the same manner. 



being set at any inclination, from per- 

 pendicular to horizontal ; and it may 

 be kept in such a position ready for 

 service, or it may be quickly packed 

 and placed in an overcoat-pocket, or 

 other small space for transportation. 

 The box is of black walnut except 

 the cover, which is of heavy plate- 

 glass. 



Mr. Griffith has already received a 

 number of orders for this microscope, 

 but has delayed filling them until the 

 instrument was perfected to suit him. 

 Probably he can now furnish them on 

 short notice. The price is lower 

 than would be expected from an ex- 

 amination of the instrument. We 

 are not sure that it is definitely fixed, 

 as yet, but it will be about twenty- 

 five dollars, including a black walnut 

 box with a plate-glass cover. 



the other immersed in a vessel con- 

 taining the water, which in my own 

 case, is a soap-dish on which I rest 

 the slides. Thus I have a perfect 

 circulation, limited only by the large 

 supply of water. The advantages of 

 this plan are that it is inexpensive, 

 and the glass slip can readily be used 

 as an ordinary slide, besides the 

 opportunity one always has, of finding 

 anything on the slide worth future 

 study, and of immediately convert- 

 ing it into a growing slide, thus avoid- 

 ing the loss of rare objects, Avhich it 

 is sometimes desirable to preserve 

 for further study. 



W. H. Wight. 



Baltimore, Md. 



o 



— A late number of the Bulletin 

 of the Torrey Botanical Club, contains 

 an article by Mr. WoUe, on New 

 American Desmids, with a plate. 



