MISSOURI BOTANICAL GARDEN BULLETIN 91 
plants not to. be watered under any circumstances, because 
of the succulent nature of the leaves. The cubic feet of 
space in the house should be exactly determined, the ratio 
to be one ounce of cyanide of potassium (98 to 100 per cent 
pure) and one ounce of commercial sulphuric acid in three 
ounces of water, to 2,000 cubic feet. Earthenware jars 
should be used, as glass jars will break when filled with the 
sulphuric acid. The water should be poured into the jars 
first, then the sulphuric acid added, and the jars placed at 
equal distances throughout the house. Before adding the 
cyanide, the steam valves should be regulated to carry the 
necessary temperature throughout the night. When these 
preparations are complete, the cyanide (previously wrapped 
in tissue paper to prevent contact with the hands) should 
be dropped into the solution by two men—one on each side 
of the house—and the house immediately vacated and 
locked, and signs attached warning against entrance. 
Next morning the doors should be left open for a few 
minutes, and then the top ventilators opened to allow the 
remaining fumes to escape. It should be borne in mind 
that cyanide is a dangerous poison, and the utmost care is 
necessary in using it in fumigation. 
LIST OF BIRDS OBSERVED IN THE MISSOURI 
BOTANICAL GARDEN DURING THE 
MONTH OF APRIL 
The birds on the following list were observed by members 
of the St. Louis Bird Club in the Missouri Botanical Garden, 
with the exception of those listed on April 19, which were 
observed by Mr. Otto Widmann: 
April 1 April 8 
American Tree Sparrow 
Bob-white Bob-white 
Brown Thrasher 
Bronzed Grackle Bronzed Grackle 
Cardinal Cardinal 
Cedar Waxwing 
Chipping Sparrow 
Crow Crow 
Downy Woodpecker : 
English Sparrow English Sparrow 
European Sparrow 
Flicker 
Fox Sparrow Fox Sparrow 
Junco Junco 
Meadow-lark Meadow-lark 
Robin Robin 
Rusty Blackbird 
Song Sparrow Song § 
Tufted Titmouse 
