278 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
concentrato the glycerin under a bell-glass by means of calcium chloride ; 
and finally mount in Kaiser’s glycerin-gelatin or Behrens’ glycerinated 
iclitliyocol. 
Cleaning Diatoms.* — M. J. Tempere gives a variety of instructions 
for obtaining diatoms in a condition perfectly free from impurities, 
including the use of a “ sieve-filter ” made of silk. 
Dr. P. Miquel t states that diatoms even of the length of 50-80 /x 
will pass through ordinary filter-paper ; and that Berzelius filter-paper 
is permeable to Cyclotellse of 13-14 /x diam. Diatoms of which both the 
longitudinal and transverse dimensions are from 20-40 /x do not easily 
pass these filters, but are liable to be drawn up by capillary attraction. 
(6) Miscellaneous. 
New Method of Separating the White from the Red Blood-cor- 
puscles by means of the Haematokrit. t — Dr. Judson Daland, in a 
Fig. 24. 
lecture delivered before the Franklin Institute, December 9, 1892, 
described a modification of the apparatus for separating the white from 
* Le Diatomiete, ii. (1893) pp. 21-6 (3 figs.). f Tom. cit., pp. 26-9. 
x Journal of the Franklin Institute, cxxxvi. (1893) pp. 204-14 (5 figs.). 
