74 INSEC'TR'IDKS, FUNGICIDES, AND WHI'.n KIELKIJS. 



ferred until the soil is neither too moist nor too cracked by the 

 heat. 



Although the painstaking observer will always be capable of utilizing 

 the sulphide against the phylloxera in no matter what ground, its use 

 is exclusively recommended in medium ground, neither too light nor 

 too heavy, neither too moist nor too dry. Just as the treatment should 

 never be applied after tillage, which by lightening the soil lets the 

 sulphide evaporate too easily, it is necessary to wait fifteen days before 

 trenching or- working. The most favourable time for treatment de- 

 pends, moreover, on the condition of the vine ; although the latter does 

 not suffer from this treatment when the dose is small, yet it is advisable 

 to choose the time when the sap is at rest. October or November is 

 preferably chosen for making injections ; February and March are 

 quite as favourable. So that the action of the sulphide be complete, 

 the vine must be allowed to reconstitute its root system by giving it 

 abundant manure, especially mineral. When the vine has been sul- 

 phuretted annually from the time of the invasion, it need not receive 

 further care than what it usually gets. 



Use of Carbon Disulphide Dissolved in Water.^The carbon 

 disulphide used in the beginning of the phylloxeric invasion, having 

 too often caused the death of the vine, it was thought that by dissolv- 

 ing the sulphide in water it would be less hurtful. The new method 

 was proposed by Cauvy in 1875, and recommended in 1882 by 

 Eommier, but it was not rendered practical until after the researches 

 of Fafeur, C. Benoit, and Duponchel. A saturated solution, i.e. con- 

 taining 0-5-l'2 per cent of carbon disulphide, is perfectly capable 

 of combating the phylloxera ; it kills it in twenty-four hours. The 

 advantages of this method are that it is perfectly harmless to the vine 

 even when it is in full vegetation, and that it can secure a uniform 

 distribution in the soil. According to Degrully, the action of these 

 solutions is the more perfect the more permeable the soil. Under this 

 form the sulphide acts quite as well as potassium sulphocarbonate and 

 has the advantage of being much cheaper ; 200 lb. of sulphocarbonate 

 employed in the same conditions as 10 gallons of carbon disulphide, 

 in 1 per cent solution, do not give so good a result. To prepare 

 a solution of sulphide, Fafeur freres have designed an apparatus 

 capable of spreading water on a layer of carbon disulphide, in 

 a closed reservoir. A current of water flows through a pipe of suitable 

 dimension drawn out to a point. The pressure obtained by the draw- 

 ing out and the speed of the current is exerted on the upper part of a 

 receiver full of water and sulphide which, owing to its density, always 

 occupies the bottom of the receiver. This pressure is transmitted to 

 the receiver by two orifices. The solution is thus produced under 

 pressure in a closed vessel by the junction in a pipe of two jets of 

 sulphide and of water, the intensities of which are always proportional 

 to each other. By opening the gauge taps the dose is regulated from 

 0-5- 1-2 per cent. The sulphuretted water is carried by buckets or 

 a long watering pipe into small holes specially dug round the stocks. 

 These holes should be well made, horizontal, and separated from each 

 other by mounds of earth so that the liquid is spread uniformly in the 



