ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 335 



serum may be poured off two or three times a day. The bougies are 

 cleaned by standing them in water, frequently changed, for some days, 

 and then sterilizing them in a muffle furnace. 



New Method of Fixing Blood-Films.* — W. F. Whitney recommends 

 a modified Zenker's fluid (potassium bichrom. 2 ; sodii sulpb. 1 ; wator 

 100 ; this is saturated with sublimate while warm and 5 p.c. glacial 

 acetic acid added at time of fusing). The author substitutes 5 p.c. nitric 

 acid for the acetic acid. The fluid is dropped on the film and allowed 

 to act for a few seconds, or while counting twenty. It is then washed 

 in running water, and afterwards the triacid stain applied for about 

 3 minutes. 



New Method for Isolating- the Typhoid Bacillus from Water .t — 

 Dr. L. Remy's method for isolating the typhoid bacillus consists of two 

 procedures, the direct and the indirect. 



A. Direct. — To a tube of differential gelatin, i.e. containing 0*5 

 per thousand H 2 S0 4 , lactose 3 p.c, phenol 0*25 per thousand, are 

 added ^, -j 1 ^, •£ ccm. of water, according to its origin. This makes 

 plate i. Plate ii. is made with the same gelatin, but contains 0'5 per 

 1000 of carbolic acid. As better results are obtained from large plates, 

 it is advisable to use, instead of 10 ccm. of gelatin, 25 or 50 ccm., and 

 add 2 • 5 ccm. of water, or more. 



B. Indirect. — 10, 20, 50 ccm., according to the water to be analysed, 

 are introduced into a flask containing carbolised acidulated bouillon. 

 The proportion should be such that the mixture of bouillon and water 

 contains 0'5 per 1000 of sulphuric and carbolic acids. After 22-2-1 

 hours at 25°-30°, differential plates are made. To these 0*25 and 

 0*5 per 1000 carbolic acid are added. The plates are kept at 20°. On 

 the second or third day the colonies may be examined. Those which 

 are deep bluish or bluish-white usually contain typical typhoid bacteria. 

 If there be few colonies, they should be re-sown in bouillon heated to 

 35°-37°. When the gelatin cube is liquefied, the tube is shaken and 

 then kept at 25°-30°. It should be particularly noted that typhoid 

 bacteria from water often form scums on bouillon. 



1(3) Cutting', including- Imbedding-and Microtomes. 



Improvised Microtome. J — J. L. Powers describes a microtome 

 devised by Dr. Shurtleff, and as it is intended for home manufacture, 

 and possibly for consumption, it may be advisable to adopt the writer's 

 own terms : — " The first essential is, of course, a knife, and while a 

 regular section razor is preferable, an ordinary razor will answer. In 

 the absence of either, however, I have seen a shoe-knife successfully 

 used, but in this case the back was strengthened by soldering a knitting- 

 needle on one side, and a rod cut from a stove-poker on the other. 

 Assuming, then, that a knife is at hand, the next requisite is the 

 holder, which consists of a piece of wood about 4 by 7 in., having 

 a U-shaped cut-out at the top, 2 in. wide and 3 in. deep. This 

 leaves two prongs each an inch wide, into which small wire nails 

 are driven, so that the razor R may rest upon them when it is in 



* Journ. Boston Soc. Med. Sci., v. (1901) pp. 341-2. 



t Ann. Inst. Pasteur, xv. (1901) pp. 145-60. See also this Journal, 1900, p. 639. 



X Journ. Applied Microscopy, iv. (1901) pp. 1163-4 (2 figs.). 



