EXPERIMENTS IN MOUNTING THE AMPHIPLEURA PELLUCIDA. 13] 
- Dichloride and tetrachloride of seleniwm.—These two chlorides 
are so very volatile and deliquescent that it is a difficult matter to 
get a film on the cover-glass, and they require further experiment- 
ing with. From the examination of several of the prepared slides, 
Chloride of ammonia.—Good, 
valves which are clean are bold and well defined—may be useful 
to sublime with other preparations. 
Chloride of thalliwm.—This is a very fine medium ; instead of 
the steel- -green colour is given to the strie ; with the 
previous medium. The valves may be seen with the central rib 
a 
greenish steel-grey, hard and crisp, the outer 
resubli 
in the piperine the resolution is as good as the iodide of arsenic. 
Nitrous acid.—On holding a pre 
mouth of a test tube whilst the nitrous acid fumes are given off a 
gives an intense yellow colour to the piperine, and o i 
e will be found to be easily resolved, and the stria wi 
