598 General Notes. [June 
with copper bars, which were heated at one end by means of a 
unsen burner, so that the heat conveyed by conduction to the 
remote end of the bars gradually diminished in intensity because 
of its being constantly radiated into the surrounding air, accord- 
ing to well-known laws stated in the text-books on physics. It 
was found that, with the room at an approximately constant tem- 
c 
cup filled with hard paraffine, the latter could be kept just at the 
point of fusion for a long time without endangering the objects 
to be imbedded. These results showed that it was possible to 
utilize an apparatus of this type for imbedding purposes. 
is led the writer of this to begin a set of experiments with 
avery simple modification of the foregoing type of apparatus, 
WAS SSNS 
-with the suk of getting rid of the usual water-bath entirely in 
the process of imbedding, and to also use the paraffine itself as 
a means to indicate how far away from the source of heat it 
would be safe to allow an object to remain while it was being 
saturated. 
This object was effected in the following manner: A triangular 
sheet of copper, slightly less than one-sixteenth of an inch thick, 
eighteen inches long, and ten inches wide at one end and running 
to a sharp point at the other, as shown at s in the accompanying 
figure, is supported horizontally upon two legs at the wide end, 
oe small Bunsen iaaa er, with an aperture o of about on ie 
of an inch, and connected with the gas-supply of the building by _ 
_ means ofa rubber tube. If the flame is allowed to burn steadily 
at about half its full force, and permitted to play upon the copper 
_ plate at a distance c of about one inch from its extreme point, as 
hown in the figure, the whole plate will soon be heated, but the 
temperature will be found to gradually diminish towards the wide > 
end. Ata distance of Wout iwole to tirnica inches from the 
