March, 1907.] Difussion of Hydrocyanic Acid Gas. 
IOI 
• The material for this paper was collected in a lagoon near 
San Antonio de los Banos, Havana Province, Cuba. Herbarium 
specimens have been deposited in the herbarium of the New 
York Botanical Garden. 
Estacion Central Agronomica, 
Santiago de las Vegas, Cuba. 
EXPLANATION OF FIGURES OF PLATE VIII. 
Fig. 1. Functional megaspore. 
Fig. 2. Two-nucleate embryo-sac. 
Fig. 3. Antipodal end of sac in which the antipodals have disap¬ 
peared; end.—endosperm. Same age as embryo in Fig. 17. 
Figs. 4 to 16. Series of embryos. 
Fig. 17. Outline of embryo same age as Fig. 3. 
EXPERIMENTS TO TEST THE DIFFUSION OF HYDRO¬ 
CYANIC ACID GAS IN FUMIGATING HOUSES.* 
A. F. Burgess. 
In February, 1906, a set of fumigation experiments was 
started to test the diffusion of hydro-cyanic gas in fumigating 
houses, with the object of determining the rapidity with which 
this gas diffuses, both in empty houses or boxes and also when 
they are filled with stock, as would be the case when they are in 
use. For this purpose permission was secured from the Agri¬ 
cultural Department of the Ohio State University to use a 
greenhouse in which soil experiments are conducted, and the 
fumigating box belonging to the Horticultural Department of 
the same institution was also furnished for the tests. 
By placing the box on a truck which run on a track it could 
be pushed outside the greenhouse. In this way it was thor¬ 
oughly aired without allowing the fumes to escape in the house 
and an opportunity was afforded to try several tests out of doors 
where the temperature was near the freezing point. 
Description of Box: The box was lined with galvanized iron 
and was 4 ft. x 2^2 ft. x 10 ft. inside measure, making a capacity 
of 100 cubic feet. 
The cover was hinged at one end and was opened by using a 
rope and pulley at the other end. It shut on strips of felt, and, 
as the galvanized iron made the cover rather heavy, it would 
close very tightly without additional weights. Clamps were 
used, however, in order to make the box perfectly gas tight. 
The generating jar was placed near the end at which the cover 
was raised, and, in order that no gas might escape while it was 
being closed, the cyanide was enclosed in tissue paper and 
dropped by a string through a small hole directly above the jar. 
* Read before the meeting of the Ohio State Academy of Science. 
