ENTOMOLOGY. 565 



root was from 18 to 29 per cent greater than tbe yield obtained on tlie cbeck plats. 

 Clover gave an increased yield on tbe treated areas, ranging from 67 to 119 per cent; 

 and in tbe case of oats tbe treatment produced, in 1891, an increase of 9 per cent iu 

 the grain and 30 per cent in tbe straw; while at Joinville, in 1892, the oats on the 

 snlplmreted plats arc stated to have shown an increase of 100 per cent in grain and 

 GO per cent in straw." 



The results the second year after the original treatment, Avithoiit 

 fnrther additions of the bisulphid or use of fertilizers, were as marked 

 as in the first year's crops. The explanation of this increased vigor of 

 plant growth is not altogether satisfactory. It is supposed that the 

 bisulphid acts as a stimulant to vegetation and also poisons subterra- 

 nean insects or other organisms, cryptogamic, perhaps, which other- 

 wise would injuriously affect the roots of plants. It may also exert 

 some chemical action on the soil elements, resulting in their easier 

 assimilation by plants. 



This latter opinion is held by 0. Oberlin, an Alsatian viticulturist,^ 

 who independently conducted a series of experiments and reports 

 results similar to those obtained by (jrirard in the increased productioii 

 of vegetables, cereals, and forage crops on land which had been sub- 

 jected to the traitemefit (V extinction referred to above. M. Whitney, of 

 this Department, suggests that there may also result an alteration in 

 the physical character of the soil which will explain the results 

 obtained. 



These results, with accompanying explanations, are in contrast with, 

 but not necessarily contradictory to, the commonly held idea that the 

 use of bisulphid of carbon is liable to stop the idtrification or conver- 

 sion into plant food of the vegetable matters in the soil by destroying 

 the microscopic germs which bring this about. That there is a check- 

 ing of nitrification by the destruction of these germs or bacteria by 

 the use of the bisulphid has been fully established by the experiments 

 of Warington, and more recently by J. Perraud,^ but there can now be 

 no doubt that the beneficial effect in some one or more of the direc- 

 tions mentioned more than offsets any retardation in the action of 

 ferments on nitrogenous fertilizers. A treatment as strong as that 

 given by Girard is impractical, costing, in fact, $90 per acre at the very 

 low price (3.^ cts. per pound) of the chemical in France, and at our rate 

 (10 cts. per pound) three times as much. But this experiment indi- 

 cates, at least, that benefit rather than injury to the soil in its produc-, 

 tive capacity is to be anticipated where the substance is employed in 

 the ordinary application in vineyards, or at about one-tenth the rate 

 given above, viz, a little less than 1 oz. to the square yard, or 290 lbs. 

 to the acre, with a minimum rate of 175 lbs. to the acre. 



The use of the bisulphid in this country in garden or vineyard opera- 

 tions can not become very general as long as the present prices are maiu- 



■ Rev. Internat. Vit. et (Enol., 1 (1891), No. 1, pp. 278-280. 



2Rev. Vit., 1894, May 5 and 12, and Rev. Internat. Vit. et CEnol., 1 (1894), No. 8, 

 pp. 307-315. 



