( ) 
“ head was fuKl of Water to z, then I clofed the out- 
“ ward Orifice of the Syphon with the End of my 
“ Finger, and at the fame time drew the other Leg 
“ of It out of the Bolt-head, by which means the 
‘‘ Water continued up to 2, and could not fubfide. 
‘‘ Then 1 placed under the Bolt-head, while it was in 
‘‘ the Water, the VefTel xx; which done, I lifted the 
‘‘ VeiTel xxy with the Bolt-head in it, out of the Water, 
‘ and tyed a waxed-Thread at 2 to mark the height 
‘‘ of the Water : And then approached the Retort 
‘‘ gradually to the Fire, taking care to skreen the 
whole Bolt- head from the Heat of the Fire. The 
‘ Defcent of the Water in the Bolt-head fliewed the 
. ' Sums of the Expanfion of the Air, and of the Matter 
‘‘ which was diftilling : The Expanfion of the Air alone, 
w hen the lower part of the Retort was beginning to 
“ be red-hot, was at a Medium, nearly equal to the 
‘ Capacity of the Retort, fo that it then took up a 
‘‘ double Space ; and in a white and almofl: melting 
‘‘ Heat, the Air took up a triple fpace or fomething 
more: For which reafon the leafi: Retorts are beft 
‘‘ for thefe Experiments. The Expanfion of the diftil- 
“ ling Bodies was fometimes very little, and fome- 
“ times many times greater than that of the Air in 
the Retort, according to their different natures. 
“ When the Matter was fufficiently diftilled, the 
“ Retort, ^c. was gradually remov’d from the Fire, 
‘‘ and when cool enough, was carried into another 
“ Room, where there was no Fire. When all was 
throughly cold, either the following Day, or fome- 
“ times 3 or 4 Days after, I mark’d the Surface of 
“ the Water y, where it then flood ; if the Surface 
“ of the Water was below 2,, then the empty Space 
“ between y and 2, fliewed how much Air was 
“ generated, or rais’d from a fix’d to an elaflick 
State, by the Adion of the Fire in Diflillation : But 
“ if 
