ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 349 



combinations are placed on a slide, a loopful of fseces is rubbed up with 

 the stain, and a cover-glass imposed. The cysts stand out as yellow or 

 greenish-yellow spheres. 



Staining Films for Spirochaetes and Treponemata.*— M. Favre 



and N. Fiessinger state that if searching for Spirochseta ictero-hsemorrhagica 

 in urine, this should first be centrifuged, and then smears made from 

 the sediment. In other cases, thin smears can be made from pus or 

 blood. Dry the preparations, and cover with the following solution : — 

 Formalin, 2 c.cm. ; acetic acid, 1 c.cm. ; and water, 100 c.cm. Leave 

 for five minutes. Wash in 95 p.c. alcohol, or absolute alcohol, and 

 apply the following mordant : — Tannin in alcohol, 4 grm., and distilled 

 water, 100 grm. Steam and set aside for thirty seconds. Wash in 

 tap-water, and rinse in distilled water. Cover films with silver nitrate 

 solution to which a couple of drops of ammonium hydrate has been 

 added. (If 5 p.c. solution of silver nitrate has added to it, drop by 

 drop from a fine pipette, a small quantity of silver nitrate, at first a 

 brownish precipitate forms, which clears on addition of more ammonia. 

 This is the proper point at which to stop.) This should be warmed up 

 as in the case of the mordant solution, and left in for thirty seconds. 

 Wash with distilled water, and dry with filter-paper. 



(5) Mounting:, including' Slides, Preservative Fluids, etc. 



Cellophane as Substitute for Glass and Mica Lamellae. — E. 

 Landau suggests the employment of cellophane as a substitute for glass 

 and mica lamellae in microscopic sections. The preparation in question 

 is pure cellulose, prepared from wood-pulp, treated with a special 

 glycerin. It is placed on the market in leaves of different thicknesses, 

 and resembles gelatin in appearance. It is insoluble in water, and is 

 unaltered by the action of air, alcohol, chloroform, and xylol, being 

 only attacked by acids and concentrated alkalies. The chief advantage 

 of this material lies in its small cost. 



• Bull, et Memoires Soc. Med. Hosp. Paris, xxxii. (1916) pp. 2070-3. 

 t C.R. Soc. Biol. Paris, Ixxx. (1917) pp. 156-7. 



