222 
BRITISH PHARMACEUTICAL CONFERENCE. 
in the same line or somewhat removed from it, might be driven by the wheel 
B, and when a pan is not in use its stirrer is simply lifted out of the wedge- 
shaped socket. 
The woodcut shows instantly liow the apparatus works in converting a 
rotary into a reciprocating motion. The latest improvement introduced has 
been in the shape of the stirrers. These are now made of such a form that 
their horizontal section gives a shape resembling the letter S» they “take 
hold ” of the water more efficiently 
I ^ IP than the flat-bladed stirrers, just as 
I // the hand when curved into a cup- 
I shape would do so more than when 
I the fingers were extended. 
Mr. R, believed that the contri¬ 
vance now shown was simpler, less 
costly, and more efiective than the 
plan of employing direct rotary mo¬ 
tion for stirring. No part of the 
metal was over the pans, and thus 
it was impossible that rust, oil, or 
other impurity could be so intro¬ 
duced. 
Since evaporation at tempera¬ 
tures below the boiling-point can 
only occur from the surface of the 
liquid, the agitation of the surface 
is our object. It must be granted 
that the backward and forward 
stroke does this much more com¬ 
pletely than a merely rotary move¬ 
ment. 
Any other motive power than 
steam might be employed, where 
this did not exist. 
Mr. Reynolds also described and 
exhibited drawings of a mechanical 
stirrer devised by Mr. T. Boverton 
Redwood. It w^as shown in action 
at a Conversazione of the Pharma¬ 
ceutical Society, in May, 1864, but 
no notice of it published. Its pe¬ 
culiarities will be evident on exam¬ 
ining the accompanying w'oodcut. 
In a short discussion, in which Mr. Giles and Mr. Carteighe took part, it was elicited 
that what was known of Lenoir’s Gas Engine was not sufficiently favourable to promise 
much for its success as an addition to small pharmaceutical laboratories. 
NOTES ON TWO MEDICINAL PLANTS PROM JAMAICA. 
BY MR. T. HARVEY. 
1. Ewpatorium {nervosum ?), “Bitter Bush.”—This native remedy is grow¬ 
ing into use and favour wdth the medical profession in Jamaica. During a 
