Furnitttre Pests. 123 



if well aired afterwards ; but as it is highly explosive he advises the use of 

 hydrocyanic acid gas as used for destroying insects under glass, etc. 



The cyanide treatment is deadly to all insect life and does not harm 

 food or anything ; but care has to be taken that the poison is not eaten or 

 the fumes inhaled by any person. 



You could only use the Chinosol for floors and crevices. 



Directions for using Hydrocyanic Acid Gas Indooi's. 



The following are instructions sent to Mr. White with regard to 

 the gas treatment. 



The proportions for hydrocyanic acid gas treatment are as follows : 

 2 ozs. of cyanide of potassium. 

 4 ozs. of sulphuric acid. 

 7 ozs. of water, 

 for 1,000 cubic feet of space. 



Proceed as follows : Add the 4 ozs. of acid to the 7 ozs. water in a 

 deep saucer or jam-pot ; then roll up the small lumps of cyanide in 

 blotting-paper and drop into the acid and water. Leave for a couple 

 of hours ; then freely ventilate the room ; do not enter it for an hour 

 after ventilation, as, of course, you must not breathe the fumes, as they 

 are deadly, and so is the cyanide. It would be safest to bury the 

 residue, but it is innocuous. You can easily manage windows for 

 ventilation, so as not to have to enter the room to do so. I should 

 put the saucer just inside the door, so the arm can reach it, and 

 drop the cyanide in blotting-paper into the saucer, shutting the door 

 immediately. Of course, do not let people stand about outside the 

 door, as some fumes may come through crevices, etc. Get the room 

 as air-tight as possible. 



The proportions I give have been found sufficient in greenhouses 

 to kill Eed Spider, Woodlice, Slugs, Aphis, and Caterpillars. 



The employment of this gas for Bud Mite in Currants {Eriophyes 

 rihis) has not proved it to be successful. Sulphur in some form alone 

 seems to affect acari. It is thus interesting to learn that fumigation 

 with hydrocyanic acid gas did not affect this household pest, but Mr. 

 White tells me he cleared it out by sulphur fumigation, 



Anohium tessellatum in St. Alban's Cathedral. 



An insect, sent by Mr. Nathaniel Hicks, in oak from the roof of 

 St. Alban's Cathedral, proved to be one of the common Wood-boring 

 Beetles — a serious furniture pest — known as the " Death Watch " 

 {Anohium tessellatum). 



