]3 



Owing to the effect of the vapour upon the heart's action, persons 

 with weak hearts should not take an extended share in the application 

 of this substance. The vapours may ignite without the presence of 

 flame at a temperature above 297° F. 



Carbon bisulphide is applicable only when the vapour can be cpiite 

 closely continetl for at least 30 minutes, and since a warm atmosphere 

 can hold far more of the vapour than a cool one, it is not advisable 

 to work at a lower temperature than 60° F., as the higher the 

 temperature the more active and susceptible to the gas the insects 

 become. Vaporisation may be hastened by applying the liquid to 

 some absorbent material hung near the top of the room or bin so that 

 the vapours may diffuse downwards, while in large warehouses the 

 liquid may be applied by means of a spray pump. The best material 

 with which to render rooms or bins air-tight is heavy wrapping paper 

 of which the edges nmst overlap, care also being taken that the corners 

 are well fitted. The fumigation of buildings is best undertaken on a 

 Saturday so that they may remain closed till Monday, thus allowing 

 of the complete diffusion of the vapours. Sacked cotton seed requires 

 special treatment [see this Review, Ser. A, iii, p. 685]. Ants are most 

 economically and effectively controlled by the use of trap-boxes filled 

 with leaves, cotton seed and straw, to wliich carbon bisulphide is 

 afterwards added ; a single trap of this kind has been found to contain 

 1,000 fertile queens. Colonies of agricultural ants may be destroyed 

 by pouring the licjuid into the opening of the nest and covering the 

 entrances with an inverted, galvanised iron tub ; from one to three 

 ounces of liquid should be used, and the tub left in position for five 

 or six hours. Ants infesting the surface soil, white grubs and mole- 

 crickets may be destroyed by making holes with a stick over the area 

 to be treated, not more than 18 inches apart and several inches deep, 

 pouring one ounce of bisulphide into each, closing them immediately 

 and covering the ground with waterproof canvas, paper, or wet blankets 

 to confine the gas. The best results against Phylloxera on vines are 

 obtained by a similar treatment applied twice at an interval of from 

 6-1 (t days, preferably in spring. The holes should be 16 inches from 

 the base of the vine, and 12-16 inches deep, fresh holes being made 

 for the second application midway between the first, and i to f oz. 

 of the liquid being injected into each. Cabbage root-maggots 

 [Chortophila brassicae] and their pupae may be destroyed by 

 distributing a teaspoonful for small plants and a tablespoonful for 

 large plants in one or two holes made not less than 4 inches from the 

 base of the plant. Aphids on low-growing plants have been 

 successfully controlled by evaporating the liquid under a tub which 

 covers the plants, the liquid being used in the proportion of one 

 teaspoonful per plant or per box of one cubic foot. Wood-borers may 

 be killed by inserting one or two drops on a small wad of cotton and 

 pushing it into the cavity as far as possible, afterwards sealing the 

 aperture with wax. Clothes, woollen and felt goods and furs may be 

 treated against clothes moths and other household insects by 

 fumigation in a tight paper-lined trunk, while the use of the liquid in 

 showcases, trays and boxes successfully wards off museum pests. 



A factor that must be taken into account in fumigation is the 

 varying resistance of different insects, for while the bumble-bee 

 [Bombus] succumbs in a few seconds, Bruchus {Pachymerus) 



