DISINFECTION BY CARBON BISULPHIDE. 



63 



the pedal. By pressing on the rod of the piston the carbon disulphide 

 is projected into the soil, then the rod re-ascends of its own accord, 

 under the action of an inside spring. The pal is withdrawn from the 

 soil, and an assistant rapidly fills up the hole with a wooden rod 

 ending in a rounded piece of iron or lead. To hasten the operation, 

 which ought to be done very rapidly, it is well to employ three work- 

 men, and to possess two pals. A workman fills the container of the 

 pal by a tap fixed on the barrel, whilst the second injects, and the 

 third plugs the holes. In vineyards arranged for the work the pal is 

 replaced by sulphide wagons or traction injectors, which do the work 

 much more rapidly, and thus economize manual labour. The mechan- 

 ism of these machines comprises a roll, acting like a pump, which 

 after drawing the carbon disulphide into a reservoir, spreads it 

 into a hollow traced by the sock of a plough, which immediately 

 covers the hollow which has just been excavated. Amongst the 

 different systems of instt'uments the most common are those of Gastine 

 of Marseilles, Vernette and Saturnin of Beziers, and Cobal of Toulouse. 



Fig. 5. — Pal-Excelsior. 



In other appliances the organs of distribution of the carbon disulphide 

 are fixed to some sort of plough. Such are the Salvator vitis of 

 Audebert of Bordeaux and the Sulfureur libouriiais of Defontaine of 

 Izou. These machines are blamed for not depositing the sulphide 

 deep enough in the soil. To secure a good distribution of the carbon 

 disulphide through the layer to be disinfected, recourse is often had to 

 1 per cent aqueous solutions. At that strength the carbon disulphide 

 is not injurious to the plant, but perfectly capable of killing subter- 

 rannean parasites. 



Disinfection in Closed Spaces. — It is used in granaries where 

 food-stuffs are stored. It suffices in that case to spread on the floor a 

 certain dose of carbon disulphide, after having closed all the vents in 

 the place. A toxic atmosphere must contain 0*5 per cent of carbon 

 disulphide. When it is required to disinfect a small quantity of corn, 

 it suffices to enclose the grain in a cask containing 0-5 per cent of 

 sulphide, and to keep the cask hermetically closed for twenty-four 

 hours. The grain sometimes retains a bitter taste after this treatment, 

 but this is removed by stirring the grain with a shovel, or by passing 

 it through the fanners. What is important to be pointed out is, that 

 the grain suffers no alteration and retains its germinative and ali- 

 mentary faculty. Carbon disulphide therefore presents real advantages 



