100 INSECTICIDES, FUNGICIDES, AND WEED KILLERS. 



Phylloxera vasfatri.r, Planch, (phylloxera of the vine). — Mouille- 

 fert found that the phylloxera dies in twenty-four hours in an 

 atmosphere containing 1 per cent of ammonium sulphide. Used 

 in small dose on a vine in pot where the whole soil could be impreg- 

 nated with this substance, the result was satisfactory, but on the 

 large scale diffusion is not so perfect, and the result was always in- 

 complete in spite of the toxicity of the two gases which form this 

 salt, ammonia and hydrogen sulphide. Mouillefert experimented 

 thus : The stocks, stripped to 30-35 centimetres (12-14 inches), were 

 watered with 400 cubic centimetres of the liquid sulphide, then with 

 10 litres of water ; after the liquid was absorbed the earth was put 

 back round the stock. On roots 50-60 centimetres (20-24 inches) deep 

 the etfect was, so to speak, nil, and it was even observed that the phyl- 

 loxeras had not been entirely destroyed on the upper roots. According 

 to Couvy and Eohart, this bad result was due to the ammonium sulphide 

 rapidly decomposing in the soil to form inert combinations such as 

 ammonium sulphate. 



Conchylis Ambignella, Hubn. (cochylis of the vine). — Dufour re- 

 commends against the grub of this butterfly a solution of 3 per cent of 

 ammonium sulphide and 3 per cent of soft soap, which he regards as 

 being more efficacious than carbon disulphide. 



20. Ammonium Sulphocyanide, NH^CNS. — Preparation. — 

 By heating potassium sulphocyanide with ammonium chloride. 



Properties. — A crystalline salt soluble in water. Its action on 

 fungi seems less toxic than that of potassium sulphocyanide. A Q-l 

 per cent solution of this salt has no bad effect on the development of 

 the uredospores of Puccinia coronata, Cord., even after an immersion 

 of twenty-seven hours. Schumann found that by watering meadows 

 with a solution of this salt, at the rate of 200 kilogrammes per hectare 

 (176 lb. per acre), the aerial part of the herbage is killed and growth 

 much weakened. 



21. Ammonium Sulphate (NHJoSO^.— Sulphate of ammonia 

 is manufactured commercially by distilling the ammoniacal liquor of 

 gasworks and putrid urine. The volatile portions are collected in 

 dilute sulphuric acid, the liquors obtained are concentrated in lead 

 tanks, where the sulphate of ammonia crystallizes in prisms. 



Properties. — Ammonium sulphate forms anhydrous permanent 

 prisms. It dissolves in 2 parts of cold and 1 of boiling water. 



Uses. — As an ammoniacal manure. 



Heliophohis poj)ularis. — Amongst the insecticides used to destroy 

 the grub of this Lepidoptera, which causes such damage to meadows, 

 Marchand found that only a 10 per cent solution of ammonium sul- 

 phate in purin gave appreciable results. 



Phylloxera vastatrix, Planch, (phylloxera of the vine). — According 

 to Hosier's experiments on the phylloxera, with the most diverse sub- 

 stances, ammonia had on these plant-lice as energetic an effect as 

 carbon disulphide and sulphuretted hydrogen, but that it had not such 

 a poisonous effect on the plant as the two latter gases. To generate 

 the ammonia gas in the zone invaded by the louse, Rosier recommends 

 to pierce holes with the pal round the vine, and to fill them either 



