1901} MICROSCOPICAL JOURNAL. 175 
ACTION oF HypRocyanic AcID on SEEDs.—Mr. CO. O. 
Townsend in a paper on the effect of hydrocyanic acid 
gas upon grains and other seeds, concludes that dry seeds 
may be fumigated with the usual strength of the gas for 
the length of time required for the infection of animal 
life, without in any way interfering with the germ power 
of the seed. Dry seed may be subjected for several months 
to the influence of hydrocyanic acid gas at the rate of a 
gram or less of KON per cubic foot without entirely de- 
stroying the ability of the seed to germinate. Seeds soak- 
ed twenty-four hours or more will not germinate in a gas 
stronger than 0.003 gm. of potassium cyanide per cubic 
foot. Seeds soaked thirty-six hours will germinate more 
readily than when soaked only twenty-four hours, but 
will not germinate in a stronger atmosphere of hydrocya- 
nic gas than 0.0003 gm. of potassium cyanide per cubic 
foot. (Bot. Gaz. 31 . 241.)—L. H. PAMMEL. 
Notes on Microscopy. 
F. SHILLINGTON SCALES, F.R.M.S. 
INSTANTANEOUS PHOTOMICROGRAPHY.—Mr, A. C. Scott, 
has devised an arrangement by which he has been able to 
obtain instantaneous photographs of microscopic living 
organisms. A powerful light is, of course, necessary,and 
in his own work he has used an arc light of 2,200 volts, 
giving about 4,000 candle-power. This light is placed at 
a distance slightly greater than the focal length of the 
condensing lens to obviate such concentration of heat as 
would be detrimental to the microscope objective. The 
camera is of the usual vertical type, but the important es- 
sential is a combined shutter and view-tube, which is 
clamped by means of three thumb-screws to the draw- 
tube of the microscope; this apparatus is fastened above 
the ocular, and after the latter has been inserted in the 
draw-tube. ‘The mechanism of this apparatus is describ- 
