In pruning care should be taken that too many main growths 

 are not left, so as not to get the vine overcrowded ; and when 

 the cut is made, see that it is close to one of the main stems. 



I find that in some gardens when the plants have had plenty of 

 soil and manure about the roots, that the vines have begun to fruit 

 on the lateral branches. In such cases, it will be the wisest plan 

 to dry the vines off for about a month by exposing the base of the 

 plants and withholding water, then they should be pruned. If 

 this fruit is allowed to remain on and ripen the vines will not be 

 able to form good new wood for another year. 



NITROGEN IN AGRICULTURE. 



Extract from an Address by DR. SOMERVILLE, at the British 



Association. 



The Chemical Fixation of Atmospheric Nitrogen. 



It has for long been the dream of chemists to discover, or wel- 

 come the discovery of, a chemical process, capable of industrial 

 application, by which the nitrogen of the air could be made avail- 

 able to replace or to supplement our rather limited supplies of ni- 

 trogenous manures. In his Presidental Address, Sir William 

 Crookes had something to say on this fascinating subject, and 

 looked hopefully to electricity to solve the problem. He pointed 

 out that with current costing one-third of a penny per Board of 

 Trade unit a ton of nitrate of soda could be produced for £26 ; 

 while at a cost of one-seventeenth of a penny per unit, a rate pos- 

 sible when large natural sources of power, like Niagara, are avail- 

 able, the cost of such artificial nitrate of soda need not be more 

 than £5 per ton.* 



Dr. von Lepel, in giving an account of recent work on this 

 subject to the winter meeting of the German Agricultural Society 

 in February of this year,t puts the cost of electric nitrate, as 

 compared with Chili nitrate, in the proportion of 24 to 39, which 

 is in close agreement with Sir William Crookes's estimate. Lepel 

 points out that the material obtained, neutralised by some alkali, 

 consists of a mixture of nitrate and nitrite. When used in pot- 

 culture experiments it has given results closely agreeing with those 

 furnished by Chili nitrate. 



Good progress would also appear to have been made in another 

 direction in the commercial fixation of atmospheric nitrogen, and 

 a short account of the results was communicated by Prof. Gerlach, 

 of Posen, to the meeting of the German Agricultural Society 

 already referred to, and is published in the same issue of the Mit- 

 theihingoi. 



When air which has been freed of ox^'^gen is conducted through 

 finely disintegrated calcium carbide at a high temperature, one 



♦ Crookes, "The VVhe-.t I'rohleni." p. 47, 



t Dr. von Lepel, Neuere Vcrsuche zur Nutzharmachuiif,' des (itniosphiiriKchen Stick, 

 stoffs durch Elektrische Flammenbogen," Mitteil de Deut. Land. Gesell., 1904, Stuck 8 



