340 BOTANICAL GAZETTE _ [OCTOBER 
thermometer (figs. 1 and 2,C). The box is provided with a specially 
constructed stand, though if desired this may be replaced by a simple 
tripod stand. Greater stability is secured, however, by having a stand 
made especially for the copper box. 
In constructing the water box it is desirable to have the top of the 
box made of slightly heavier sheet copper than the bottom, 14 oz. 
copper for the bottom and 16 oz. copper for the top being satisfactory. 
By observing this precaution, all bulging due to water expansion or 
water pressure will manifest itself on the lower side, and a plane surface 
is maintained on the upper side, which of course is essential for good 
imbedding. 
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Fic. 2—Top view of apparatus 


In using the apparatus the box is first filled with water and the water 
" supply then shut off. The box is heated by a Bunsen flame, and when 
_ the desired temperature is attained, as indicated by the thermometer, 
the flame may be removed. A constant temperature may also be main- 
tained by continuous heating and then regulating the flow of water; 
this latter being the better method. ‘ 
After the material has been oriented, it is rapidly cooled by replacing 
the warm water with a stream of cold water. If paper trays have been 
used for imbedding, they may be sufficiently cooled for removal and 
immersion in water in 30 seconds. For bringing the stand to the proper 
temperature the same time is required. The top of the box should of 
course be kept free of paraffin.—L. Knupson, Cornell University, I thaca, 
New Vork. 
