ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
113 
Thermo - Regulator for Petroleum Heating.* — Dr. P. Altmann 
describes an apparatus by which a thermostat can bo maintained at a 
constant temperature where the source of heat is not gas. It consists of 
a contact thermometer, tho tube of which is immersed in the water space 
of the incubator. At the top of the tube is a box with dial and two 
hands, one of these is fixed at any desired temperature. As the 
temperature of the incubator rises, the free hand moves until it touches 
the fixed hand. This makes an electric contact, and a current passes to 
the other part of the apparatus. Here by means of an electromagnet 
and a lever two mica plates are made to close over the lamp in such a 
way that the heat is directed away. As the temperature of tho thermostat 
falls, so does the free hand of the contact thermometer fall away from 
the fixed hand, and then the contact is broken, whereupon the mica 
plates fall back, and the heat reaches the thermostat again. The 
apparatus works quite automatically, and is said to maintain a constant 
temperature. 
Apparatus for Obtaining Samples of Deep SeaWater and from the 
Sea Bottom.! — Mr. H. L. Bussell describes an apparatus which he has 
used with very satisfactory results, for collecting samples of deep sea 
water. It consists of a large-sized test-tube, tightly fitted with a rubber 
cork, having a single hole. The opening in the cork is closed by a glass 
tube, which projects about 3/4 in. below the lower end of the stopper. 
The upper part of this small tube is bent at right angles to the long axis 
of the collecting tube, and drawn out to a fine calibre. The various 
parts having been carefully sterilized, are fitted together, and a partial 
vacuum produced either by means of an air-pump, or by just heating 
the tube. The end of the tube is then sealed. To prevent the ingress 
of air, the cork should be coated with a mixture of beeswax and resin. 
Samples of water are obtained by clamping the tubes to a holder in 
such a way that the drawn-out end lies close to the connecting line. 
When sunk to the desired depth, a lead messenger is sent down the 
connecting line. This catches the end of the fine tube, breaks it off, 
and destroys the vacuum. The tube then fills with water. There is no 
danger of the sample getting mixed with water from other depths, as 
the tube is effectually stoppered by means of imprisoned air. 
The apparatus used for obtaining material from the sea bottom 
consists of an iron tube (gas-pipe) pointed at one end. The other end is 
fitted by means of a screw with a removable “ sleeve,” the upper end of 
which is closed by a valve. As the weighted instrument descends, 
the water passes through the pipe, and when the bottom is struck, the 
pipe is forced into the soil, and so fills with a compact mass of material. 
When withdrawn, the water-pressure closes the valve, and prevents the 
contents from being washed out. Though the apparatus is theoretically 
imperfect, it practically delivers samples of the sea bottom quite uncon- 
taminated. 
Puritas Water Filter. t — Dr. M. Jolles, from experiments with 
Micrococcus prodigiosus , finds that the Puritas Water Filter is only 
* Centralbl. f. Bakteriol. u. Parasitenk., xii. (1892) pp. 654-5 (2 figs.). 
f Bot. Gazette, xvii. (1892) pp. 312-21. 
i Centralbl. f. Bakteriol. u. Parasitenk., xii. (1892) pp. 596-605. 
1893, t 
