CAEBON DISULPHIDE. 73 



(say 8000 holes per acre) must ever be made, nor less than 40,000 

 (16,000 per acre) in land only slightly permeable. A distance of 

 30-40 centimetres (12-16 inches) is generally kept from the foot of the 

 vine, so as to avoid wounding the large roots. In many cases, how- 

 ever, deep injections can be made at 20 centimetres from the stock. 

 The amount of sulphide injected per hole depends on the number of 

 injections per square metre. At Libourne, for example, only 12 

 grammes is injected per hole, say 160 kilogrammes (352 lb.) per 

 hectare(141 lb. per acre), instead of the dose of 200 kilogrammes (440 lb.) 

 per hectare (176 lb. per acre) usually employed in the Ehone, where 

 the vines produce in consequence of this methodical treatment as 

 beautiful crops as before the invasion of the phylloxera. The dose 

 to use depends, moreover, on the depth of soil and the age of the vine. 

 If it be desired, like Monestier, Lautaud, and d'Ortomann, to bathe all 

 the root system in a toxic atmosphei'e, three holes must be made 1*2 

 metre (4 feet) deep, the roots of certain vines being more than 1 metre 

 (3-28 feet) in length. Cabanel and Degrully, however, advise not to 

 go beyond a depth of 50 centimetres (say 20 inches). In compact 

 soils 20 centimetres (7'8 inches) is enough. When holes are made in 

 the immediate neighbourhood of the stock as the tendency is now, a 

 depth of 8-10 centimetres (3-4 inches) is not exceeded. The greater 

 number of vineyards is treated by the pal-injector. In large vineyards, 

 however, the plough is employed as follows : In vineyards where the 

 lines are a metre (3-28 feet) apart, two turns of the plough are given 

 between the lines. Each line of treatment is 25 centimetres (10 inches) 

 from each row of stocks. In the case of vines planted at greater intervals 

 care is taken to maintain the distance of 25 centimetres from the stocks 

 for the first line, the others are 50-60 centimetres (20-24 inches) from 

 each other, but it is best not to approach the rows of vines too closely, 

 for at 5-10 centimetres (2-4 inches) they suffer from the injections. 

 Sulphuretting ploughs were introduced with great enthusiasm, but they 

 did not give the results anticipated. That is, because in spite of their 

 ingenious arrangement, the carbon disulphide cannot be introduced to 

 any depth, without meeting and wounding the roots. The great ad- 

 vantage of these improved insti'uments consists in the fact that a man 

 and a horse can treat | hectare (1| acre) with them in a day. The 

 work, moreover, is very uniform as regards distribution and dose, especi- 

 ally with intermittent jet drainers. The latter, especially, have the 

 great advantage of greatly facilitating the diffusion of carbon disulphide 

 which is projected with force, and which is divided almost instantane- 

 ously. The efficiency of the treatment by carbon disulphide depends 

 especially on the nature of the soil, and Degrully is of opinion that there 

 exists for each soil a propitious moment favourable to the uniform 

 distribution of carbon disulphide ; this moment should be observed and 

 chosen by the vine-grower. In permeable or sandy soil, cracked or 

 too dry, the carbon disulphide will escape without producing its effect. 

 But in compact moist or clay soils it does not spread enough and 

 remains concentrated around the holes, thus destroying a portion of 

 the roots in their neighbourhood and remaining without effect on a 

 great part of the soil affected. The treatment must therefore be de- 



