834 OC. M. Warren ona Process of Fractional Condensation. 
The upper end, A, of the elevated worm is brought out through 
the side of the bath at a point about three inches below the top; 
so that, when working with a low temperature of the bath, the 
worm may still be completely covered with oil, and also give 
sufficient space above the worm for the expansion of the oi 
when higher temperatures are employed. ‘T'o avoid contami- 
nating the atmosphere of the laboratory with the disagreeable 
fumes which are given off, in large quantity, from such a mass 
of heated oil, the top of the bath is tightly closed with a sheet- 
iron cover, from which a small funnel, A, fig. 1, conducts these 
fumes to a chimney. 
In the larger apparatus, the vapors which succeed in pasa 
through the heated worm. are conducted downward into a coole 
shown in fig. 1. 
For collecting liquids which boil below the common tempera: 
ture, when such are present, I attach a refrigerator, B, fig. 2, 
—one 
? 
2, which communicates with the first receiver, &, by meaus f 
the glass tube, m. f 
In order to successfully collect and condense the vapors 
such extremely volatile liquids as are now under consideration, 
it is of course indispensable that the apparatus should be con 
structed with very tight joints; and for greater convenienc®, 
but more especially to prevent breakage, such of the jon 
require to be frequently taken apart should be made flexible 
A very convenient and perfectly tight joint of this kind ~ 
be made as follows:—the short stationary tube, n, 1n the ae a 
of the receiver, 4, fig. 2, is made with the opening somes : 
vergent upward; the end, 0, of the worm is enough smé 
an the inside diameter of the upper end of the tube, %, ! 
leave room for a piece of caoutchouc tube to be drawn over ess 
and still admit of its being inserted in the end of the tube, "3 
. 
m coming in conti” 
with the caoutchouc; a perfectly tight and convenient flexible — 
