19S 
BllITISH PHARMACEUTICAL CONFERENCE. 
the liquid,—1 grain of heavy carb. magnesia was added to each of the fol¬ 
lowing liquids in tubes of similar size and shape :—water, rectified spirit, ether, 
chloroform. In the two latter, the magnesia took a somewhat clotty condition, 
and settled rapidly, the liquids differing greatly in their density, but both 
having great mobility. In the two former (water and spirit) the subsidence 
was much slower, and there was no tendency to clot, the liquids occupying a 
position between the two former, as regards density, but being inferior to them 
both as regards mobility. 
The experiment was repeated, substituting fine powdered charcoal for mag¬ 
nesia. The subsidence was in all cases slower, but the relation before observed 
was still maintained. In the water and spirit subsidence was not more com¬ 
plete in twenty-four hours than it was in the chloroform and ether in as many 
minutes. The charcoal also appeared a little clotted in the chloroform. We may 
conjecture that the great mobility of chloroform facilitates the action of the ag¬ 
glomeration forces, while its density subtracting from the effect of gravitation 
allows them time to manifest their action. 
The recent experiments of Mr. Crookes, showing how readily mercury may 
be divided when its surface is tarnished by sulphuretted hydrogen, and how 
readily it again unites when sodium is supplied to abstract the sulphur, suggests 
that we should look for a film upon the surface of the globules of emulsified oil, 
and that materials which cause the separation of the oil, may do so in virtue of 
a power of dissolving or decomposing this film. 
In concluding these observations, let me express a hope that some other mem¬ 
bers of the Conference will add a few notes to my own. On the list of subjects 
for investigation it is stated that I will be glad to receive communications upon 
this subject. I have not received a line from any one. I cannot but think 
that many gentlemen may have fragments of information which while isolated 
appear valueless ; let me assure all my fellow-members that no observations are 
too fragmentary or isolated to be thankfully received. To any one engaged in 
an investigation the most trifling matter is not to be overlooked, and commu¬ 
nications always act as an encouragement and stimulant to continued work. 
11, Grey Street , Neiocastle-on-Tyne , July , 18G5. 
The President spoke of this paper, as worthy of the author, whose logical, consci¬ 
entious, and painstaking habits of thought were already known to the members. The 
paper afforded much matter for reflection. 
Mr. Sciiacht said that the present paper recalled to his mind some experiments which 
he had made a few years ago upon the phenomena known as molecular motion.* No 
object exhibited these singular movements more definitely than the ink of the cuttle-fish. 
He (Mr. S.) had ventured to theorize somewhat after this manner:—these effects are 
only produced when very finely divided matter meets with a compatible liquid of nearly 
coincident specific gravity, and their greatest and most prolonged development takes 
place when the two substances are such as have a tendency to combine. So far from 
accepting the idea that had once been promulgated, that the explanation lay in some 
exercise of repulsive energy, he believed that the same force of molecular attraction that 
effected the solution of a solid in a liquid where the properties of each made that end 
possible, in these instances, where solution was not possible, produced results which were 
due to mutual attempts of the particles to satisfy an attraction which could not, how¬ 
ever, be satisfied: hence, a condition of perpetual unrest. 
* Pharm. Journ. vol. xviii. p. 375. 
