444 Mr, Faraday on new compounds 
0°; many of them became turbid, probably from the pre- 
sence of water; one, received at 176®, (by which is meant 
that that was the boiling point of the contents of the retort 
when it came over) became partly solid, crystals forming 
round the side, and a fluid remaining in the centre ; whilst 
two other portions, one received at 186°, and the other at 
190°, became quite hard. A cold glass rod being introduced 
into one of these tubes, the mass within was found to resist 
considerable pressure ; but by breaking it down, a solid part 
was thrust to the bottom of the tube, whilst a fluid remained 
above : the fluid was poured off, and in this way the solid 
portion partly purifled. The contents of the tube were then 
allowed to fuse, were introduced into a larger and stronger 
tube, furnished with another which entered loosely within it, 
both being closed of course at the lower end ; then again 
lowering the temperature of the whole to 0°, bibulous paper 
was introduced, and pressed' on to the surface of the solid 
substance in the large tube by the end of the smaller one. In 
this way much fluid was removed by successive portions of 
paper, and a solid substance remained, which did not become 
fluid until raised to 28° or 29°. To complete the separation 
of the permanently fluid part, the substance was allowed to 
melt, then cast into a cake in a tin foil mould, and pressed 
between many folds of bibulous paper in a Bramah's press, 
care having been taken to cool the paper, tin foil, flannel, 
boards, and other things used, as near to 0° as possible, to 
prevent solution of the solid substance in the fluid part to be 
removed. It was ultimately distilled from off caustic lime, 
to separate any water it might contain. 
The general process, which appears to me to be the best 
