DISEASES OF THE VINE. ] 601 



impaired and the vine dies. A newly infected vine 

 usually shows no sign of disease, but in the following 

 year or sometimes late in the same \ear, it is noted that 

 the shoots remain small, with small leaves, which turn 

 yellow and dry off very early in summer and in the 

 second or third year the vine dies. In the meantime 

 the vines around the centre of infection are already in- 

 fected, and succumb soon after, the infection spreading in 

 concentric lines until the whole vineyard is destroyed. 



In order to check the spread of the evil it has been 

 suggested to uproot and burn all the vines within the 

 infected area, including those vines which are as yet 

 apparently healthy, to burn the vines on the spot 

 along with their roots and foliage, and to disinfect the 

 soil by means of bisulphide of carbon or petroleum, 

 which should be injected deep into the soil, and the sur- 

 face of the ground rolled over, to maintain as long as 

 possible the action of the disinfectant. Carbide of 

 calcium, or the residues left after the production of acety- 

 lene pras, or a mixture of carbide of calcium and phos- 

 phate of lime (phospho-carbide of lime), have been used 

 with some success against the Phylloxera, owing to the 

 poisonous nature of the gas (hydrogen phosphide) which 

 is developed It was also suggested, where possible, to 

 inundate the vineyard for four to six weeks, keeping the 

 water at about 10 cm. above the level of the soil all that 

 time. But these various methods of treatment, and many 

 others which were tecommeded from time to time, have 

 afforded very little relief from the ravages caused by this 

 insect, and have h rdlv help- d to check its spread in 

 those countries where it had obtained a footing The 

 only true remedy consists n grafing the European \ine 

 on American vines or American hybrids of proved resist- 

 ance to the disease, or by planting American hybrids 

 4 'direct producers", that is which are capable of produc- 

 ing fruit of the right quality for the table or for the 



