GERMAN COCKROACH. 83 
being deterred from continuing traffic through by the use of ordinary 
plaster, make some stronger preventive necessary, I have found it answer 
to fill these with plaster of Paris mixed with a weak solution of sulphate 
of copper, sometimes known as blue vitriol, or blue-stone. I mixed a very 
little of the plaster at a time in a common sized tea-saucer, and with 
a flexible paper or palette knife filled in as much of the crack as the 
plaster would reach to as quickly as possible, then washed the saucer 
(that the setting of the next mixing might not be spoiled), and so pro- 
ceeded, mixing fresh and filling, until the cracks were stopped. If a 
few little bits of the blue-stone were left in, it was all the better. The 
plan is a little troublesome, but I found it to answer well when I 
carried it out myself. 
In the following note, kindly given me at my request as to how 
the ‘‘ stoving,”’ mentioned at p. 29, was carried out, it will be observed 
that a mixture of carbolic acid with imewash was applied to the walls 
as one of the operations after the fumigation, and doubtless the 
earbolic acid might be utilized as a deterrent of Cockroach travelling 
through, or sheltering in, crevices :— 
Fumigation.—“ The stoving process destroyed a great number of 
the little Steam Flies, as I call them, but does not exterminate them 
entirely. Keating’s insect powder is also good, and stuns them, but 
they must be swept up and burned, or they come round again. I had 
the joiner to come to stove the kitchen and scullery two nights, using 
about eight pounds of brimstone each night. Of course, before 
‘stoving,’ he pulled down all wooden shelves and casements that 
might be protecting gas or water pipes; then, of course, made up all 
crevices in doors and windows, also fireplace. After that I had the 
walls limewashed, and put carbolic acid into the lime*; and I must 
say, after all the trouble, we had very few of the vermin left. I did 
not see the man stove the kitchen; but I believe the sulphur is 
put upon an iron plate,—over shelves, for instance,—or an old pail 
in the middle of the room where it is to be used, and then set fire to, 
carefully pasting up every crevice of the door when you come out of 
the room.”’ 
The following note on a safe and simple method of preparing 
sulphur fumes, taken from a pamphlet on ‘The Flour Moth,’ issued 
by the Ontario Board of Agriculture, may be of service :— 
‘«‘To prepare sulphur fumes: place a metallic dish containing hot 
ashes on some support in a pan of water; or place in an old pan, or 
other vessel, a bed of ashes at least six inches deep and about fifteen 
inches in diameter, and place the sulphur and saltpetre in a slight 
depression in the centre, and ignite. The proper proportions are: 
* The italic type is my own addition to draw attention to the mixture.—Ep. 
D 
