476 . 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
the haematoxylin, and differentiated in 1 per cent, solution of iron-alum 
to a bright but delicate blue. 
Study of Blood-Corpuscles.* * * § — Prof. P. Owsjannikow, in his study 
of the blood-corpuscles of the crayfish and the fresh-water mussel, made 
use of some reagents which he is able to recommend. A drop of blood 
was placed in one or two drops of iodised serum on a slide. It was 
then covered with a cover-glass, which, at all four corners, was provided 
with a little wax foot. A drop of anilin solution is gradually intro- 
duced into the blood. The addition of glycerin will prevent the drying 
of the preparation. A one per cent, solution of osmic acid may have 
soluble stains added to it, but such stains as are not soluble in spirit 
must be avoided. Corpuscles were well fixed with a 1 or 2 per cent, 
solution of formalin. With hypermanganate of potash in a 1 per cent, 
solution the deposit is so finely granular that it does not affect the 
investigation. 
Investigation of Caudina arenata.t — Mr. J. H. Gerould calls 
attention to the use of magnesium sulphate as a stupefying reagent. 
A specimen of Caudina having been allowed to become well expanded 
in a small quantity of sea-water, crystals of magnesium sulphate were 
added, a small teaspoonful at a time. If contraction occurs, the salt is 
added more slowly, or the use of it suspended entirely until the animal 
again expands. Perenyi’s fluid gave better general results in killing 
than any other of the reagents which were employed. Previous to 
imbedding an object in paraffin, it was often found necessary to remove 
bubbles of carbonic acid gas which had gathered in the tissues during 
decalcification. This was accomplished, as suggested by Cuenot, by 
placing the specimen under the receiver of an air-pump, and exhausting 
the air. For staining on the slide nothing was found to surpass Ehrlich’s 
haematoxylin followed by eosin. 
The author has given what he believes to be a thorough trial to 
the rapid method of Golgi, but without the slightest success. However, 
the author thinks that the method, which is so fruitful when applied to 
other animals, deserves a more extended trial with echinoderm tissues 
than has been given it ; for the Golgi method may capriciously fail when 
employed in the study of one animal, although it affords excellent results 
when applied to a closely related form. 
Demonstrating Tubercle Bacilli in Sputum.J — Prof. v. Eindfleisch 
moistens an ordinary camel-hair brush with water and then stirs up the 
sputum with it. YVhen withdrawn it usually looks as if there were 
nothing on it, but if cover-glasses be smeared therewith, the film will be 
found to contain a relatively large number of tubercle bacilli. Of 
course a new brush must be used each time. 
Demonstrating Tubercle Bacilli in Human Sputum.§ — Herr E. 
Hacke says that the following procedure will be found to be very simple 
* Bull. Acad. Imp. Sci. St. Petersburg, ii. (1895) pp. 367-70. 
f Proc. Boston Soc. Nat. Hist., xxvii. (1896) pp. 9-10. 
X Deutsche Med. Woehenschr., xlviii. (1895). See Zeitschr. f. angewandte 
Mikr., i. (1896) p. 346. 
§ Zeitschr. f. angewandte Mikr., ii. (1896) pp. 1-4. 
