892 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
are inhibited while their life is preserved. Three grams of white 
gelatin are dissolved by heating in 100 com. of water; the result is a 
stiff jelly at the temperature of the room. In this, about 3 per cent., 
gelatin solution, which may be diluted if desired, the movements of 
Paramsecium and Urostyla are prevented, but the cilia and the con- 
tractile vacuoles remain active for hours. For observing the movements 
a solution of 1 • 5 per cent, is most useful ; for vivisection experiments 
* 8-1 per cent. 
(3) Cutting-, including Imbedding and Microtomes. 
Hard Section Cutting and Mounting.* — Mr. J. W. Dunkerley 
recommends the following process, which is specially adapted for deal- 
ing with large specimens, such as horse’s teeth, as well as smaller ones. 
“ Sections are cut off the tooth by means of a thin copper disc, fitted in 
the ordinary manner on to a dental lathe, and revolving in a tin trough 
which contains water and fine corundum powder. This thin disc is now 
replaced by a thick one, with the same trough and contents ; the sides 
of this disc are used as a lapidary stone to grind thinner these sections, 
one side of which is next polished on a soft stone (Water of Ayr) under 
running water, this surface being afterwards secured to a glass slip 
by thick Canada balsam. The grinding of the section on the thick 
copper disc is now proceeded with until the section is thin enough to 
see the structure ; then proceed to polish this surface on the Water of 
Ayr stone until all details are seen under the Microscope, when after 
careful washing the section is mounted.” 
Fig. 105. 
Rapid Method of Dehydrating Tissues before Infiltrating with 
Paraffin.! — Mr. G. L. Cheatle describes a modification of Soxhlet’s 
* Journ. Brit. Dental Assoc., xiii. (1892) p. 581. 
f Journ. Pathol, and Bacteriol., i. (1892) pp. 253-5 (1 fig.). 
