ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
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the most part separated out, only a few remaining in the milk and 
cream. 
Collecting Samples of Water for Bacteriological Analysis.* — Dr. 
W. Johnston describes in detail his method of obtaining samples of 
water from any depth, free from contamination and with great ease. 
The collecting apparatus, which is a modification of that invented by 
Prof. Ellis, is very ingenious. It consists of a framework holding a 
sterilized glass bottle, and so weighted that it can be lowered to the 
required depth. By pulling a string attached to the stopper the latter 
can be raised sufficiently to allow the water to enter. When the string 
is released, the stopper is instantly replaced by the action of a spring. 
For further details of this simple and ingenious apparatus the original 
must be consulted. 
Method of obtaining Pure Cultivations of Tubercle Bacilli from 
the Sputum, f — Dr. E. Pastor first ascertains if the sputum contains a 
good quantity of bacilli and relatively few foreign organisms ; the patient 
is then made to repeatedly wash his mouth and the back of his throat 
out with sterilized water, and then to expectorate into a sterilized vessel. 
The sputum thus obtained is emulsified by shaking it up with sterile 
water, and any coarse particles filtered off with fine gauze. A few drops 
of the filtrate are then mixed with fluid 10 per cent, gelatin, care being 
taken that the medium is not rendered too cloudy. The still fluid 
gelatin is then poured out into plates, and these, just covered with a 
bell-jar, are left at the room temperature. In the course of three to four 
days colonies of bacteria spring up. By means of a lens parts of the gelatin 
which remain quite clear are then sought out. These are then carefully 
excised with a sterilized knife, and inoculated on obliquely-set blood - 
serum. Of ten blood-serum tubes inoculated in this way the author 
obtained always one, and in some several, pure cultivations of tubercle 
bacilli. In the rest of the tubes impurities appeared owing to the 
development of germs, which at 37° ‘5 and on blood-serum overpowered 
the tubercle bacilli. 
From the fluid contents of phthisical cavities, of course, better results 
are obtained, as this material contains not only more bacilli but less 
impurities. 
(2) Preparing Objects. 
New Method of Preparing Sections of Teeth and Bone, to 
demonstrate the hard and soft tissues in combination 4 — Mr. A. 
Hopewell Smith writes : — “ Immerse a newly extracted tooth in Muller’s 
fluid for three to four weeks, and remove to spir. vini rect. for ten to 
twenty days. Alcohol (84 per cent.) may be used instead of Muller’s 
fluid. Remove, wash in water, and seal up apical foramen with collo- 
dion. Place tooth in 15 ccm. of following solution: — HC1, 12 parts; 
HN0 3 , 30 parts; aq. dest., 108 parts. Take 12 ccm. of 10 per cent, 
solution of HC1, and at end of fifteen hours add 1-5 ccm. of HN0 3 , and 
at end of forty-eight hours add 1*5 ccm. of HN0 3 from commencement 
* Canadian Record of Science, 1892, pp. 19-28 (1 pi. and 5 figs.), 
t Centralbl. f. Bakterio). u. Parasitenk., xi. (1892) pp. 233-4. 
j Trans. Odont. Soc. Gt. Britain, xxiv. (1891) p. 20. 
1892. 2 H 
