422 ANNUAL KECORD OF SCIENCE AND INDUSTRY. 



phur is most efficient, and that the method of applying this, as 

 is customary, in its crude form, does not meet the needs of 

 the case, as it is not carried sufficiently far into the soil to act 

 upon the insects. We must, therefore, resort to some very 

 soluble and assimilable chemical compounds, and this is best 

 done by using in succession two different liquids, the mutual 

 decomposition of which will result in the separation of the 

 sulphur in a nascent state. 



Two processes are suggested by him for accomplishing the 

 result. In the first of these he waters the foot of the vine 

 with a solution of a soluble hyposulphite belonging to an al- 

 kaline or alkaline-earthy series. As soon as the acrid solu- 

 tion, in penetrating the soil, has reached the roots, he waters 

 them anew with a solution containing a sufficient quantity 

 of the acid phosphate of lime, soda, or potash, since the ex- 

 cess of the phosphoric acid saturates the base of the hydro- 

 sulphite originally employed, thus producing the nascent sul- 

 phur. 



In the second method he waters the plant either with a 

 hydrosulphate of sulj^hur, or with any other sulphate of the 

 alkaline or alkaline-earthy series. As soon as this solution 

 has penetrated the soil sufficiently to bathe the roots, he ap- 

 plies a solution containing a sufficient quantity of soluble hy- 

 posulphate to produce the nascent sulphur by double reaction. 

 The same solution may be employed, alternately, for water- 

 ing the trunk, the branches, or the leaves even, as well as the 

 roots of the plant, with the object of destroying parasites. 

 3 B, August 7, 1873, 596. 



EFFECT OF TOPPING POTATO STALKS. 



Comparative experiments, to determine whether cutting 

 off the stalks at the commencenient of the potato disease 

 protected the tubers without diminishing the yield, were 

 made by Paulsen, by raising one row and topping another 

 on the same day, at regular intervals. While the result 

 showed that the separate rows, by like treatment, without 

 disease, varied in yield, the topped plants had for the most 

 part a larger proportion of large tubers than those that had 

 been raised on the same day. It seems, however, that only 

 water is taken up by the tubers after topping, since no in- 

 crease of dried matter was found when the topping occurred 



