258 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
velocity dependent on the inclination of the section to the optic axis ; 
which is greatest (negative crystal) or least (positive crystal) when the 
light propagates itself at right angles to the optic axis, and is equal to 
the constant velocity of the ordinary wave when the light proceeds in 
the direction of the optic axis. 
If we accept Fresnel’s fundamental data, the constant velocity of 
propagation of the ordinary wave must correspond to a constant property 
of the substance in the direction in which the vibration takes place. 
In the basal plane, however, the vibrations must take place in all 
directions in the same way, because — as stated above, a plane wave 
propagated at right angles to this plane behaves like ordinary light, 
which proceeds in the crystal with the velocity of the ordinary wave. 
The only supposition possible is, then, that the vibrations of the 
ordinary wave take place in the basal plane, and that consequently 
the direction of vibration of plane polarized light is at right angles to 
the plane of polarization. 
(6) Miscellaneous. 
Fifteenth Annual Meeting of American Microscopical Society. — 
This meeting was held in August last, at Rochester, N.Y., under the 
presidency of Prof. M. D. Evvell, whose address dealt with some relations 
of the Microscope and Jurisprudence. Twenty-seven papers were com- 
municated, and six prizes, varying in value from 50 to 15 dollars, have 
been put at the disposal of the Society. The President for the ensuing 
year is Prof. Jacob D. Cox. 
Scottish Microscopical Society. — This young society has published 
in a separate form some of its Proceedings, reprinted from the ‘ Journal 
of Anatomy and Physiology’ (vol. xxv.). The pamphlet is mostly 
occupied with an interesting address, by Prof. Rutherford, its second 
President, on the Tercentenary of the Compound Microscope. Prof. 
Sir W. Turner was the first President, and Dr. Rutherford has been 
succeeded by Prof. Struthers. 
p. Technique.* 
Cl) Collecting Objects, including Culture Processes. 
Coco-nut- Water as a Cultivation Medium. f — Dr. J. N. Davalos 
opens the nuts in the usual way, pouring the fluid into a vessel, and 
then distributes it into flasks or test-tubes, which are afterwards discon- 
tinuously steam sterilized. If the nut be unripe the reaction of the 
coco-milk is neutral, but later it becomes acid. If the fluid be made 
alkaline with soda, potash, or ammonia, a coagulum, which must be 
filtered off, forms. When the fluid, alkalized and filtered, is steamed 
under a pressure of 1J atmospheres it remains clear, but takes on a 
mahogany colour. This is probably the effect of heat on the glucose. 
* 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. ; 
(G) Miscellaneous. 
t Crbnica Medico-quirurgica de la Habana, 1892, No. 11. See Centralbl. f. 
Bacterio!. u. Parasitenk., xii. (1892) pp. 766-9. 
