Notes . 
542 
to be bleached are placed. In the first bottle a sufficient quan- 
tity of crystals of chlorate of potassa is placed to cover the 
bottom, and about a drachm of strong hydrochloric acid is poured 
upon them. The gas, saturating the water, safely and effectually 
bleaches the seaions. A notch is cut in the cork of the second 
bottle, to allow the escape of the gas when the water becomes 
supersaturated. The process is condudted out of doors, and 
exposure during the night is sufficient to bleach the sections. 
The washing is conduced in a bottle of the same kind. A funnel 
passes through the cork, and is continued to the bottom of the 
bottle by means of a piece of india-rubber tubing.. A small hole 
is drilled in the side of the bottle, about half an inch below the 
shoulder. The seaions are placed in water in the bottle, a filter- 
paper is placed in the funnel, and the whole placed under a tap 
arranged to allow of a suitable flow of water. The washing 
will be found complete after a night’s exposure. In the dis- 
cussion which followed Mr. W. H. Gilburt remarked that the 
bleaching and staining processes were not altogether satisfaaory, 
because, if the relation of the tissues to each other was to be 
observed, it was necessary to do something more than bleach 
them, and when cell-contents had to be examined it was neces- 
sary to do so in their natural condition, and the tissues should be 
as fresh as possible. Dr. John Matthews said there was a mode 
of differentiation of tissues which was too often overlooked, and 
that was the use of the polariscope. If the objecff under exami- 
nation did not yield to one selenite, it usually would to another. 
Mr. F. Barnard, of Kew, Viaoria, writing to “ Science 
Gossip,” recommends the use of carbolic acid in place of tur- 
pentine for preparing objeas for mounting in Canada balsam. 
It has the advantage of not rendering tissues brittle, as is the 
case with turpentine, and allows objeas to be mounted in balsam 
without previous drying. 
Erratum. 
Page 406, line 13, for “ coon ” read “ born.” 
