580 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
d, which in itself moves vertically on the body by means of two slots 
fitted to the screwheads q and q'. When the weight W falls, it is guided 
by the copper] wire o , upon which the apparatus is lowered, and falls 
upon the bar d, breaking the tubep> square across. The other parts are 
— 8, a steel spring clip, and h, the knob which fastens R and U together. 
A, fig. 45, shows the collecting tube after the water sample is pro- 
perly taken ; and C, another form of sampling tube. The total weight 
of the apparatus is about six pounds, and it is thus self-sinking. 
A complete vacuum should not be made in the tube, because it is 
not desirable that the latter should be entirely 
filled with water. There is always water enough 
left in the small tube (A) to shut off the ex- 
ternal air. 
Bottle for Immersion-Oil and for Canada 
Balsam.* — Herr A. Meyer has invented a glass 
dropping-bottle which appears to be very suit- 
able for immersion-oil and for Canada balsam. 
Its construction and appearance will be easily 
understood from the above illustration (fig. 46), 
from which may also gathered that it is dust- 
proof, and that if upset, the contents will not 
run out. 
Elask for Bacteria and High Tension. — 
Mr. F. J. Reid sends the accompanying sketch 
(fig. 47) of a flask which he has found most use- 
ful with bacteria and high tension currents. Its advantage consists in 
its having the short neck at the side, into which a thermometer can be 
* Zeitsclir. f. wiss. Mikr., xiv. (1897) pp. 174-£ (3 figs.). 
Fig. 47. 
