Sept. 1894.] 



GENERAL AGRICULTURAL NOTES. 



75 



Discussing the immediate causes of the increased yield, 

 M. Girard thinks it may be within the bounds of possil3ility 

 that the carbon bi-sulphide acts as a stimulant to vegetation ; 

 but he suggests as a more natural hypothesis that the specific 

 in question acts as a poison to insects and lower organisms 

 inhabiting the soil and attacking the roots of plants. Perhaps 

 that may be the case; but there is apparently no direct 

 evidence to show that the sulphide exercises an action directly 

 deleterious to micro-organisms. On the contrary, some micro- 

 organisms are said to be capable of resisting its action, and, as 

 an example of this, mention is made of the bacteria found at the 

 roots of leguminous crops ; for it was in the case of clover, the 

 roots of which were in every case loaded with nodules, that 

 the increased yield was most marked in the experiments referred 

 to above ; the same remarks apply generally to agents capable 

 of fixation of nitrogen, nitrifying microbes, etc. As a matter of 

 fact, the crops of 1891 and 1892 were obtained without the 

 addition of any manure. M. Girard is unable to express any 

 opinion on the question as to the action of the sulphide upon 

 the cryptogamic growths which occur so frequently upon 

 the roots of plants. This point, it appears, has not hitherto 

 been the subject of thorough investigation. Until further 

 researches have been made, he inclines to the view that the 

 carbon bi-sulphide acts principally upon insects which inhabit 

 the soil and obtain their food by gnawing and wounding the 

 rootlets, whose function it is to supply the foliage of the plant 

 with nutriment. This view of the mode of action of the 

 sulphide is stated to be strikingly confirmed in the actual 

 practice of sulphuration in large doses. As the treatment 

 proceeds, numbers of insects of all kinds are seen rushing here 

 and there, struggling to escape, but they succumb eventually 

 to the effects of the sulphurous vapour. 



As regards the practical application of the treatment for the 

 purposes of agriculture, M. Girard points out that doses of 

 carbon bi-sulphide, such as those referred to above, are absolutely 

 incompatible with the conditions of ordinary agriculture ; they 

 represent a cost amounting oven at the lowest estimate to more 

 than 16^. per acre; but he questions whether doses so strong 

 are absolutely essential, and whether there may not be a point 

 at which the cost is compensated by the increased value of the 

 crop. M. Girard hopes to be able to throw some light upon this 

 subject before the end of the present year. 



Production of Wool in Victoria. 



In an article in the Victorian Year Book 1893 on the production 

 of wool in Victoria, Mr. Hayter, C.M.G., the Government statist 

 of the Colony, states that the general lambing season in Victoria 



