402 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
of heat ; (B) dissolve 1 grm. of haematein in 50 grm. absolute alcohol. 
Mix the two while still warm, allow to cool and filter. (2) Wash 
in water ; (3) stain with Ziehl 15 minutes ; (4) anilin hydro- 
chlorate 2 per cent, a few seconds ; (5) decolorize in alcohol ; (6) xylol ; 
(7) balsam. 
After decolorizing the preparation may be contrast-stained in aqueous 
solution of aurantia or of Indian yellow in order to show up the red 
corpuscles in the blood-vessels and the protoplasm. 
Hew Method for Detecting Tubercle Bacilli in Phthisical Spu- 
tum.* — Dr. K. Ilkewitsch dilutes about 1/2 ccm. of sputum with 20 ccm. 
distilled water and some drops (8-12) of a 30 per cent, solution of KHO. 
When by the aid of heat and constant stirring the sputum is completely 
dissolved, some casein, which has also been dissolved by heat-stirring, 
and 1-2 drops of KHO, are added. This imparts a milky appearance to 
the hitherto transparent fluid. The mixture is then poured into a test- 
tube, a few drops of acetic acid are added, and the whole is transferred 
to a brass tube (about 20 ccm. contents), the end of which is conical. 
The tube is then fixed in the centrifuge by means of a special apparatus 
devised by the author, but which is unimportant so far as the principle 
of the process goes. After centrifuging for 5-10 minutes the sediment 
which has collected in the conical end is removed by unscrewing the 
cap. The cap is just like the end of a pencil or stylograph, and the 
sediment is prevented from escaping by dropping down a little ball 
which shuts it in during removal. . The sediment is then removed, spread 
on cover-glasses and treated in the usual manner. 
The principle on which the foregoing method is founded is derived 
from the fact that casein of milk (lactoglobin) is of all proteids the 
most sensitive to the action of acetic acid. Hence in this mixture of 
casein, sputum, and acetic acid, the casein is the first to coagulate, and 
accordingly, after centrifuging, so much sediment is obtained as casein 
has been added. 
Investigation of Blood of Necturus and Cryptobranchus.t — Miss 
E. J. Claypole prepared the tissues of these Amphibians by hardening 
them according to Prof. Gage’s picric-alcohol method — 95 per cent, 
alcohol 250 ccm. ; water 250 ccm. ; and picric acid crystals 1 grm. 
After two or three days the animal was transferred to 67 per cent, alcohol 
for from 24 to 36 hours, and then placed in 82 per cent, alcohol. For 
imbedding, small pieces were dehydrated in 95 per cent, alcohol for 
12 to 24 hours, soaked in chloroform for the same time, infiltrated four 
to five days in an incubator, and imbedded in pure, hot paraffin. For 
acid staining, hydrochloric acid carmine was found to be most successful. 
Investigation of Ancylus.j; — M. E. Andre found grave disadvantages 
in the two methods often recommended for fixing Gastropods — the use 
of picro-sulphuric acid or boiling sublimate. He found that he got the 
best results by placing the animals on their ventral surface on the bottom 
of a capsule containing a very little water, and then killing them by 
suddenly adding boiling water. They should then be placed in a tepid 
* Centralbl. f. Bakteriol. u. Parasitenk., xv. (1894) pp. 162-5. 
f Proc. Amer. Micr. Soc., xv. (1893) pp. 66 and 7. 
X Kev. Suiss. Zool., i. (1893) pp. 429-31. 
