2 
subsequently place for 5 hours in each of the following, 70-, 
80-, 85-, 90°/, alcohol. 
If the process “a” be employed, it will be necessary to 
treat sections, before staining them, for 5 minutes with an 
iodine-iodide of potash solution. 
Then transfer to absolute alcohol in which the tissue is 
to remain for 6 hours, after which it should be placed into 
fresh absolute alcohol for another 6 hours. 
5) Pour off most of the alcohol leaving only sufficient to cover 
the tissue and run pure chloroform down the side of the 
vessel to form a layer at the bottom. After some time the 
tissue will be found to have sunk to the bottom of the tube, 
when the fluids must be poured off and fresh chloroform added. 
After 6 hours change the chloroform once more and allow 
the vessel to remain uncorked for about 2 hours on the warm 
chamber, when any alcohol, that may remain, will have eva- 
porated. 
6) Saturate the chloroform gradually with solid paraffin first at 
the ordinary temperature, then at 25° C and lastly at 52° C. 
For the first two stages allow 4 hours and for the last 
stage at least 10 hours, keeping the bottle always well 
stoppered. 
7) Remove the stopper to allow the chloroform to evaporate 
gradually. Avoid the use of exhaust-pumps and similar de- 
vises, or considerable shrinkage is sure to result. 
8) The tissues should not be exposed to the heat of the hot 
chamber for a longer time than is absolutely necessary, other- 
wise they are apt to become brittle. 
A few hints on the mounting of sections may not be out of 
place: Prepare a number of microscopical slides by allowing a twice- 
filtered 8°/, solution of white of egg to run over one side. The 
slides are then allowed to dry and stored in a dry place till required. 
The sections are spread on warm water at 40° C by GuLLAND’s me- 
thod !), the prepared slide is dipped into the water and the sections 
arranged on the albuminised side as desired. If the slide be next 
placed on the warm chamber for 10 minutes the sections will adhere 
sufficiently to be taken through any staining medium. Sections are 
ultimately cleared in resinified turpentine and mounted in turpentine 
balsam. 
1) Journal of Anatomy and Physiology, Vol. XXVI, p. 56. 
