750 REPORT—1896. 
position of chloral hydrate with a solution of carbonate of soda. These solutions 
were used in the following proportions :— 
50 c.cm. 5 solution of chloral hydrate were mixed with 
4 c.cm, 5 solution of carbonate of soda, 
and three drops of a solution of sesquichloride of gold (1°5 per cent.) added. Ata 
temperature of about 22° the reaction takes place, the so-called liquid gold sepa- 
rates out in the form of a violet solution. With this solution, and with the appa- 
ratus described, it is not difficult to find reactions which form the ‘dead space. 
Care must be taken, however, to exclude direct solar rays. } 
The ‘dead space’ is probably caused by internal resistance of the fluid. Ina 
liquid, inclosed by a hard wall, the motion of the liquid will be the more hindered 
by the friction produced by this motion itself the smaller the vessel is. Not that, 
of course, any change is assumed in.the coefficient, but the conclusion seems 
inevitable that the smaller the space inclosing a fluid, the more nearly the fluid 
resembles a solid as regards its internal resistance. 
The same must hold good in the case of an inclosed fluid, where the upper wall 
is bounded by the surface-tension of the fluid, and also in the case of a fluid 
bounded only by its own stretched circumference—i.e., the case of the drop. 
This view of the change in the physical qualities of fluids is illustrated by some 
friction-experiments, 
If a small disk-shaped float, having the smallest possible upward pressure, be 
allowed to rise in a glass vessel, it will be seen to come to an apparent standstill 
half a millimetre below the surface, and then to rise to the surface with greatly 
diminished velocity ; a proof that there is friction on the fluid side of the stretched 
surface, 
The second experiment consists in allowing a concentrated coloured glycerine- 
solution to rise in a colourless glycerine-solution of slightly greater density. Ifa 
glass tube, fitted at its upper part with a prism filled with the heavier solution, be 
used, the current of the liquid shows the direction taken by the ‘dead space,’ and 
thus indicates the places at which the fluid-resistance is at its maximum, J 
Thus we are brought to the conclusion that liquid friction is of influence in 
the phenomenon of chemical reaction, and that in small inclosed spaces—spaces in 
which the fluid is, as it were, solidified—the reaction is retarded. 
It is worthy of consideration whether these observations have not an important 
bearing also in relation to biological processes. : ! j 
Attention has long since been directed by the chemist and physiologist alike 
to the question whether there are not modes of reaction in the limited spaces of 
organisms differing from those observed hitherto in the larger vessels of the chemica} 
laboratory. t 
The results given tend to show that the small space of the cells is not 
accidental, but that it has a function either to moderate or to stimulate 
chemical reactions, or even to determine their direction otherwise than in larger 
vessels, 
Chemical reaction, thus modified, may well play an important réle in cells, and 
it is hoped that not only in pure chemistry, but also in the chemistry of vital 
phenomena, further investigations on the lines suggested may lead to important 
results, 
3. Excrescent Resins. By Professor M. BaMBERGER. 
4. Report on the Proximate Chemical Constituents of the various kinds 
of Coal.—See Reports, p. 340. 
