C. M. Warren on a Process of Fractional Condensation. 335 
joint is now made by pressing the tube, n, over the caoutchouc 
covering of the end of the worm, 0. The joints of the receiv- 
ers, WJ, are made in the same manner. 
The vapors which escape condensation in @ pass through the 
receivers, ke and Jl, to the refrigerator, B, which contains ice, or 
mixture of ice and salt, are there condensed and fall back 
into the receivers, 7; which should stand in a wooden vessel 
also containing ice or a freezing mixture. The refrigerator, B, 
_ismade with double bottom and sides, with an inch space be- 
_ tween, which is filled with pulverized charcoal. Being tightly 
covered, a charge of ice and salt will serve for a long day's 
operations without renewal. In this manner I have been able 
to collect, in considerable quantity, bodies boiling nearly at 0° 
€., and this from mixtures in which such bodies had been quite 
_ beyond the fire-place, and the dropping of the sheet-iron apron 
_ Would cause an additional draft, and thus insure the passage of 
ee such as described for the safety-lamp.’ 
 Btze upon the bottom need not be permanently attached to the 
~ farnace, but may be simply laid over an opening cut in the stool 
i oe * ; 3 d 
__, for an apparatus to stand upon the table, the safety lamp an 
a fornace are mecsinlly deaabihe T have also use them for pe 
: larger apparatus, placed upon the floor of the jaboratory. 
ony ; 
aes ' This Journal, 1862, [2], xxxiii, 275. 13 Loc. cit. 
