ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
271 
solutions neutralized in this way, the filtrate is quite clear and 1 litre 
of fluid is obtainable in about 15 minutes without having recourse to the 
hot water filter. A portion of the filtrate, which should still give an 
alkaline reaction with phenolplithalein, is mixed with an estimated 
quantity of acid, e. g. for cholera cultures the most favourable acidity 
is that which is equivalent to 16 ccm. 1/10 acid in 100 ccm. gelatin. 
Sputum as Cultivation Medium for Pneumonia Cocci.* — Dr. A. 
Schmidt finds by cultivating pneumonia cocci on sputum that note- 
worthy differences occur in the microscopical appearances. When grown 
in agar small bacilli, devoid of capsules, with tendency to form chains, 
appear, while on sputum the cocci assume the form as observed in the 
body and blood of infected animals. Inoculations from agar cultures to 
a sputum-medium reproduce the well-marked capsule bacilli. Pneumonic 
sputum, which is highly albuminous, was treated as serum, the only 
difficulty being the presence of air-bubbles. The most suitable sputum 
was that before the crisis. It was sterilized by heating it five times to 
55° for one hour at a time. 
Nastukow, M. M. — Eigelb als Nahrstoff fur ,Bakterien. (Yellow of Egg as a 
Nutrient Material for Bacteria.) Wratsch , 1893, pp. 912-4, 950-1 [Russian]. 
(2) Preparing- Objects. 
Method of Preparing Fresh Sections of Brain.f — Dr. Middlemass 
recommends a few alterations in Bevan Lewis’s excellent method of 
cutting fresh sections of brain. He advises that the sections should be 
floated out on to ice-cold water as soon as they are cut, as it prevents 
any considerable breaking up of the section. The result is still better 
if sufficient solution of permanganate of potash be added to the water to 
give it a fairly dark-red colour. With thick sections it is especially 
necessary to free them as much as possible from water. As anilin-blue- 
black is not a pure chemical substance, but a mixture, the best way to 
get a good stain is to take one which already gives a fairly satisfactory 
result, make a saturated watery solution of it, and pour it into a con- 
siderable quantity of absolute alcohol. This is quickly filtered, washed, 
and dried. The black amorphous powder which is precipitated dissolves 
completely in water, and gives a more delicate and a blacker stain than 
the original, while its action is more uniform. 
Investigation of Spermatogenesis of Salamandra.J — Dr. 0. vom 
Path reports that, in addition to better known aids to preservation of 
the testis, he got particularly good results with a mixture of picric-acetic 
acid and platinum-chloride-osmic acid. This mixture was prepared by 
adding 500 ccm. saturated watery and filtered solution of picric acid, 
3 ccm. of acetic acid, 5 grm. platinic chloride (dissolved in about 5 ccm. 
of water), and 2 grm. crystalline osmic acid. The testes were placed 
whole in this mixture, and, after they had become hardened to a certain 
extent, they were punctured with a fine entomological needle, whereby 
the preservative fluid and, later on, stains, xylol, and paraffin were the 
better able to enter. After staying t for three to five days in this mixture 
it was washed off with methyl-alcohol, and the objects were placed for 
several days in absolute alcohol which was several times renewed. Some 
* Centralbl. f. Klin. Med.,xiv. p. 625. See Centralbl.f. Bakteriol. u. Parasitenk., 
xv. (1894) pp. 70-1. t Proc. Scott. Micr. Soc., 1892-3, pp. 86-8. 
X Zeitschr. f. wise. Zoo!., lvii. (1893) pp. 102 and 3. 
