CARBON BISULPHIDE, 65 



saprophytes as parasites on different plants. To disinfect a vine- 

 yard it is advisable to proceed as follows : After having staked out the 

 ground by metric divisions, two holes per metre 25-30 centimetres 

 (10-12 inches) in depth are made with a pal and 100 grammes 

 (S^ oz.) of carbon disulphide are injected into each. In compact soils 

 four holes are made, each of which receives 50 grammes of sulphide. 

 It is always well to water the ground after this operation, so as to 

 maintain the carbon disulphide as long as possible in the soil. This 

 treatment is generally carried out in winter, and the vines are re- 

 planted the following spring. Carbon disulphide is not applied against 

 any other cryptogamic diseases, but it possesses, however, a certain 

 action on the spores of fungi. Dr. Delacroix in his researches on the 

 F'usarium Dianthi (P. et D.) observed that the conidia are killed 

 after seven hours in an atmosphere saturated with carbon disulphide, 

 and that the chlamydospores are destroyed after twelve hours. The 

 spores of fungi resist the action of carbon disulphide much better 

 than insects, but it is not impossible that the sulphide will yet find 

 some applications for the destruction of certain fungi refractory to 

 the action of the different cryptogamic bouillies. 



Use against Anguillulideae (Eelworms). — Heterodera Schachtii 

 (nematoide of beetroot). — Kuhn, who has principally studied this 

 parasite, believes that the exhaustion of the soil in beet cultivation is not 

 due, as is generally imagined, to the want of potash or other elements 

 necessary to intensive cultivation, but exclusively to the exaggerated 

 development of this eel. Eotations are powerless to destroy this parasite, 

 because it lives quite as well on other plants. Willots' experiments 

 with gas liquor only gave incomplete results. Carbon disulphide, 

 tried in the year 1875, was not recommended until 1877 by Aime 

 Girard, after he had discovered its surprising effects. In Germany, 

 Hollrung also got good results by the use of this insecticide, but 

 provided it was used in a large dose, that is to say, of 1-8 metric tons 

 per hectare (say 1584 lb. per acre) spread in the holes placed regularly 

 50 centimetres (20 inches) apart. 



Heterodera radicicola, Greff. (root eel worm). — Dussuc recom- 

 mends for the destruction of this eelworm the cultural treatment 

 used against the phylloxera. The different nematoides that live on 

 the roots of all these plants of large scale agriculture, and which 

 neither deep cultivation nor rotations can destroy, contribute in great 

 measure to create that peculiar state of soil known as exhaustion. In 

 these conditions when their presence in very great number is re- 

 cognized in a soil, it is well to have recourse to a complete disin- 

 fection of the soil, using massive doses of carbon disulphide. This 

 treatment will maintain the fields in good condition for several years, 

 especially if care be taken not to convey thereon farmyard manure 

 liable to contain eelworms. 



Use against Insects. — Insects, the larvae of which live at the 

 expense of the roots, may be destroyed by carbon disulphide used in 

 the conditions indicated to destroy the phylloxera. 



Melolontha vulgaris (cockchafer). — In carbon disulphide an in- 

 fallible remedy has been found for the destruction of the larvas of 



5 



