582 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
water flows by the tube a as quickly as it flows out through h to the 
compressorium. As the water does not remain long in the heating 
apparatus, it is not deprived of much of its dissolved air. A thermo- 
meter and thermostat also dip into the vessel. 
Another form of apparatus suggested by Prof. Ziegler consists of a 
long glass worm contained in the heating apparatus. As the water 
passing through this worm does not acquire the same temperature as the 
bath, its temperature is taken before it enters the compressorium. 
New Knife-holder for Microtomes.* — Prof. S. Apathy gives the 
following requirements for a perfect knife-holder for a sliding micro- 
tome: — (1) It must hold the knife quite firmly ; (2) the knife-edge may 
be set at any desired angle in the plane of motion ; (3) the knife-edge 
to be parallel to the plane of motion ; (4) the blade of the knife may be 
inclined at 0°-20° ; (5) the knife may be taken out of the holder and 
replaced again in exactly the same position. A holder satisfying these 
conditions — especially (2) and (4) — is described in detail. The in- 
clination of the knife to the plane of motion is effected by means of 
wedges. 
Cheap Condensing Lens. j — Instructions are given for making a 
cheap mount for a bull’s-eye condenser. A spectacle maker’s cataract 
lens is fixed by sealing wax in a loop made from a strip of metal ; this 
is attached by a wire passing through a cork to a vertical wire on a 
wooden base. 
(4) Photomicrography. 
Simple Apparatus for Photomicrography.]: — Mr. M. J. Golden de- 
scribes a simple wooden base, consisting of a long board, to which are 
attached a shelf to hold the Microscope, and a sliding piece with a pair 
of brackets to carry the camera. A heavy cloth funnel connects the 
Microscope and camera. 
(6) Miscellaneous. 
Diamond for Cutting Glass Discs.§ — Dr. C. J. Cori describes a 
simple and cheap apparatus for cutting glass discs of various sizes, which 
are always of use in laboratories. It is constructed on the principle 
of the beam-compasses. The fixed centre consists of a wooden cylinder of 
2 cm. diameter, held to the glass by wax ; about this rotates the hori- 
zontal prismatic beam, which carries a block holding the diamond. 
Annuli of glass may be cut with the apparatus. 
B. Technique.|| 
(1) Collecting Objects, including Culture Processes. 
Closing Fishing Net.1T — Dr. C. J. Cori describes a form of net which 
may be opened at any depth, and, after being trawled for any required 
time, closed again, thus enabling the organisms from any depth to be 
* Zeitschr. f. wiss. Mikr., xiv. (1897) pp. 157-74 (9 figs.). 
t The Microscope (Washington), v. (1897) pp. 109-11 (1 fig.). 
j Tom. cit., pp. 103-4. 
§ Zeitschr. f. wiss. Mikr., xiv. (1897) pp. 175-7 (1 fig.). 
|| This subdivision contains (1) Collecting Objects, including Culture Pro- 
cesses; (2) Preparing Objects ; (3) Cutting, including Imbedding and Microtomes ; 
(4) Staining and Injecting; (5) Mounting, including slides, preservative fluids, &c. ; 
(6) 'Miscellaneous. ^ Zeitschr. f. wiss. Mikr., xiv. (1897) pp. 178-84 (3 figs.). 
