338 REPORT OF THE HORTICULTURAL DEPARTMENT OF THB 
THE FORMULAE. 
The following formula is recommended by Sirrine for general 
use in fumigating well-matured dormant nursery stock. For 
each 100 cubic feet of space in the room use: 
FoRMULA FOR WELL-MATURED STOCK. 
Potassium cyanide, $8 to 99% pure........ 1% oz. (avoir.) 
Sulphuric, seid ee... pile on 2 cits ois ete ee 1%, to 11% fl. oz. | 
IW alery aFes ater tia ts* gece ye eae ot aeccns aes Gaels 4% fl. oz. 
Fumigate for one hour and then ventilate the room ten min- 
utes before entering it. 
Sirrine’s experiments with different amounts of the cyanide 
lead him to the opinion that for general use with well matured 
nursery stock the amount should not be less than 14 oz. per 100 
cubic feet, which is the amount given in the above formula.’ 
He finds, however, that stock, under some conditions, is injured 
by even as small a quantity of the cyanide as this. Johnson 
reports similar results and recommends for peach whips, June 
budded peach trees, bud sticks and in general all stock which 
is not well matured; that the amount of potassium cyanide be 
reduced to 18 grams (approximately 2 oz.) per 100 cubic feet.® 
When stock is to be fumigated which is not well matured it is 
doubtless best to reduce the amount of the cyanide as Johnson 
recommends, even if it is necessary to lengthen the time of 
fumigation to get satisfactory results. Following Sirrine’s ideas 
in regard,to the proportionate amounts of sulphuric acid and 
water the formula for each 100 cubic feet of space would be as 
stated below. 
°In this formula Mr. Sirrine recommends more sulphurie acid and water 
to each ounce of potassium cyanide than is called for in some other for- 
mule which have been recommended by other entomologists. 
Other entomologists recommend less amounts of the cyanide. Johnson’s 
formula calls for approximately i oz per 100 cubic feet; Alwood uses 
1 oz., Marlatt 1 oz. and Webster % oz. per 100 cubic feet for well matured 
stock. . 
‘Johnson, W. G. 1. e, 
