1-26 INSECTICIDES, FUNGICIDES, AND WEED KILLERS. 



water, distributed in four holes 60 centimetres deep placed in a radius of 

 35 centimetres around the stocks. The dose of 20 cubic centimetres 

 of sulphocarbonate of 33° B. sufficed to kill the phylloxera without 

 injuring the vine, but it is preferable to use per stock 50-80 

 centimetres of sulphocarbonate at 37*2° B. dissolved in 10 litres of 

 water to obtain complete success. 



Use. — Sulphocarbonates were examined so as to be utilized in 

 vine-growing in the destruction of the phylloxera. The results 

 obtained against this louse by snlphocarbonation led to this treatment 

 being tried on other insects on which it has also given good results. 



Phyllo.rera Vastatrix, Planch, (phylloxera of the vine). — History. — 

 In the seance of 8 June, 1874, Dumas proposed the sulphocarbonates 

 for the destruction of the phylloxera, indicating at the same time a 

 practical method for their manufacture. The Department of Agri- 

 culture and the Academie des Sciences entrusted therefore two delegates, 

 Cornu and Mouillefert, to make the necessary experiments to de- 

 termine if the predictions of the learned chemist would be realized. 

 Mouillefert made numerous experiments at the Cognac Viticultural 

 Station, and was able to conclude that the sulphocarbonates, and 

 especially potassium sulphocarbonate, were marvellous insecticides and 

 also the best remedy against the phylloxera. In his remarkable re- 

 search on the chemical products proposed for the destruction of 

 the phylloxera he places the sulphocarbonates in the first rank 

 of efficiency, and declares them to be alone capable to keep a vine 

 attacked by the phylloxera in a thriving condition, and to regenerate it 

 if weakened by the disease. 



In numerous experiments on vine stocks placed in different condi- 

 tions of soil, age, and cultivation, the sulphocarbonates always effected 

 an improvement. Those greatly attacked by the phylloxera had lost 

 all their root hairs, and of which a part of the radicles was attacked 

 were, after a year's treatment, finer plants than the non-diseased stocks. 

 The stocks still more badly diseased and almost in the last extremity 

 were appreciably improved and did not die like the untreated blanks. 



Mouillefert in 1876 published the conditions which it is indispens- 

 able to observe to secure good results by this treatment. The useful 

 application of alkaline sulphocarbonates to the cure of the vine re- 

 quires : (1) That all the infected surface be treated. (2) That the 

 poison be injected deep enough to I'each all the phylloxera. The best 

 method to secure perfect diffusion in the soil is to use water as the 

 vehicle. The amount used may be greater, or less, according to the 

 state and conditions of humidity in the soil, and according as it may be 

 expected to rain, or not, but water cannot be completely suppressed. 

 The more water added, the more complete the diffusion and rapid the 

 action. The amount of sulphocarbonate required to treat a square 

 metre to a depth of 80 centimetres, 31*2 inches, which gives 800 litres, 

 say 1 cubic yard, of soil, is 30-40 cubic centimetres, 1-lJ fluid oz., 

 which is comparatively very little. Without the aid of water it would 

 be very difficult to distribute this small volume on the surface of the 

 soil and equally impossible to cause it to descend to a sufficient depth 

 to kill all the insects unless the soil be very permeable or rain falls at. 



