62 INSECTICIDES, FUNGICIDES, AND WEED KILLERS. 



it one of its most precious properties, that of its great diffusibility. 

 A slower evaporation will not create an atmosphere sufficiently toxic 

 tj kill the parasites. A great number of volatile substances, very 

 poisonous to the phylloxera and used in the same conditions as carbon 

 disulphide, have never been able to equal it, as their diffusion in the 

 soil was too slow. To avoid the loss of carbon disulphide in the usual 

 treatment with the pal-injector, the use of gelatinized capsules con- 

 taining a dose has been tried. These capsules are arranged in holes 

 made with a pal-injector, and afterwards plugged. Under the action 

 of the moisture of the soil the gelatine finally dissolves, the sulphide 

 flows out into the soil and rapidly evaporates, The operator has thus 

 a convenient time without fearing loss of the sulphide to plug the 

 holes and to water the surface of the soil to imprison the vapour 

 after the rupture of the capsules. In spite of the apparent advantages 

 of this process, it has had to be renounced in viticulture because the 

 disengagement of sulphide was too irregular and not simultaneous in 

 the zone treated. In horticulture these capsules are handy because 

 they ai'e easy to use and as they avoid the purchase of a pal-injector. 

 (4) To distribute uniformly the sulphide in all the soil to be treated. 

 This is done by placing the holes at equal distances from each other, 

 and by using instruments which enable equal doses of this substance 

 to penetrate into the soil. Carbon disulphide may be injected into the 

 soil during almost the whole year. However, it is less injurious to 

 the plant if the operation be performed during the time vegetation is 

 at rest. In any case, its use should be avoided during the flowering 

 period and when the fruit approaches maturity. 



Instruments Necessary for applying Carbon Disulphide. — The 

 pal-injector already mentioned must be placed in the first rank of 

 instruments intended for this purpose. It is a sort of compression 

 pump, intended to convey a known dose of carbon disulphide to a 

 certain depth. The Jjol-Gastine^ which may serve as a type, consists 

 of a reservoir, in zinc or copper, intended to contain carbon disulphide. 

 This instrument possesses, in its interior, the body of a pump in which 

 a piston moves. Under the pressure of the latter a valve opens and 

 closes the opening of a long channelled tube, which penetrates into 

 the earth. An aperture near the sharp end lets the sulphide escape. 

 Two handles and a pedal serve as a point of support to the workman. 

 The output can be regulated at will. In hard and gravelly soils the 

 workman is preceded by an assistant, who pierces the holes with an 

 iron crowbar called Avaiit-jxtl, the tube of the pal-Gastine not being, 

 sufficiently solid for this purpose. To avoid this drawback, Vermorel 

 has improved this pal and has invented the pal-Excelsior, which 

 differs from the foregoing by the fact that the valve is placed in a 

 lateral tube by which it is possible to have a much stronger perforating 

 tube. To regulate the quantity of carbon disulphide it suffices to give 

 a longer or shorter course to the piston, by intercalating washers in 

 the body of the pump. By this means the j^ci^-E^c^^^i'Or can be 

 regulated at will for an output of 5, 6, 7, 8, 9, and 10 grammes of carbon 

 disulphide at each injection. In actual sulphurization the pal is 

 seized by the two handles, then sunk in the ground by the help of 



