ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 339 



Fresh malaria blood-films fixed iu alcohol are stained by this mix- 

 ture diluted with 2 to 4 volumes of water in 5 minutes without heat, 

 followed by gentle heating for 5 to !0 minutes. For Trypanosoma 

 blood the mixture is used undiluted, or diluted with 2 volumes of water. 



(6) Miscellaneous. 



Platinum Needles with Capped Handles for Bacteriological Pur- 

 poses.* — Prof. A. Meyer says that it is advantageous to have a platinum 



Fig. 63. 



— -o 



a 



a.. 



cap to needle-holders. The cap, as shown in the illustration (fig. 63), 

 fits over the end of a glass handle. The needles may be straight, with 

 a loop or with a spatula end. 



Convenient Source of Artificial Light for the Laboratory Table.f 

 — W. Krauss has devised an easily adjusted light for the laboratory 

 table which does not interfere with daylight. The device consists in 

 reflecting the light of a ground glass incandescent bulb from a mirror 

 arranged at a convenient angle. The bulb may be placed on the table 

 or beneath it. In the latter case a trapdoor must be cut in the table 

 and the mirror fixed to the under surface of the flap. 



Ostwald's Thermoregulator.J — Th. Paul has adapted W. Ostwald's 

 thermoregulator to incubators. The apparatus, which is extremely easy 

 to manage and of simple construction, consists of two parts, a tube 

 and a top-piece. The tube is filled with 10 p.c. chloride of calcium 

 solution. The top-piece is practically a U-shaped tube containing 

 mercury, one arm of which is connected with the calcium chloride 

 cylinder and the other with the gas arrangement. 



The special advantages are that it is easily cleaned and that it 

 works very satisfactorily. 



Paraffin Blocks for Celloidin Sections.§ — W. W. Babcock has found 

 that paraffin with a high melting ■ point forms a ready and suitable 

 basis for celloidin blocks. The paraffin cake is scored on one surface 

 by a series of oblique incisions, with another set of incisions at right 

 angles. In this way a surface is covered with slanting teeth sufficient 

 to hold the celloidin block when stuck on in the usual way. 



Camera Lucida for Counting Blood-Corpuscles.|| — Dr. A. L. Bene- 

 dict recommends the camera lucida for counting blood-corpuscles. The 

 lines of a hsemacytometer are drawn on a piece of cardboard by means 

 of the camera, and the count made by reflecting the lines back on to 



• Centralbl. Bakt., 1" Abt., xxix. (1901) pp. 260-1. 



t Journ. App. Microscopy, iii. (1900) pp. 1086-7 (1 fig.). 



% Centralbl. Bakt., l ,e Abt., xxix. (1901) pp. 129-33 (1 fig.). 



§ Journ. App. Microscopy, iii. (1900) pp. 1090-1. || Tom. cit., pp. 1087-9. 



