THE SOUTHERN PLANTER 



pound gas formed of nitrogen and dydro- 

 gen, was it requisite that they should ap- 

 ply to the soil artificially that which was 

 so abundantly supplied by nature ? Had 

 not plants .the means of obtaining from 

 the atmosphere all the nitrogen, and 

 from the water in the soil, all the hydro- 

 gen, essential to their development and 

 perfection? Again, the lecturer stated 

 that land was less injured by a double 

 cropping of clover than by being frequent- 

 ly eaten by sheep and cattle ; since, with 

 the growth of the plant above the soil, 

 there was a corresponding increase of 

 roots beneath, which roots afforded a large 

 supply of manure lor the succeeding crop. 

 Was not the effect of carrying off a large 

 amount of alkalies and phosphates in the 

 two crops of clover more than any equiv- 

 alent afforded by the accumulation of 

 roots ? and was the carbonaceous matter 

 produced by the roots at all required by 

 the wheat grown after the clover, seeing 

 that, according to the lecturer's statement, 

 the atmosphere would afford in the form 

 of carbonic gas all the carbon the plant 

 would require ? 



Mr. Nesbit, said, the first question was 

 whether it was not desirable that bone- 

 dust, when applied as a manure, should 

 be applied on the surface, and not plough- 

 ed in too deeply. His reply was, that it 

 would be the best not to plough in the 

 bones too deeply, because they would not 

 in clay soils of this district decompose 

 quickly ; but with decomposed manures 

 the question mighty be different. The 

 more the bones are exposed to atmospheric 

 action the better, and that was the reason 

 why it should be finely powdered as pos- 

 sible. The second question was, whether 

 ammonia existed atall as ammonia in farm- 

 yard manure ? Ammonia certainly did 

 not exist as such in a piece of straw ; 

 but as soon as the straw began to decom- 

 pose, ammonia was produced, a portion 

 of the nitrogen and hydrogen of the straw 

 or other decomposing matter uniting to- 

 gether to form ammonia, while the carbon 

 and a portion of the hydrogen united with 

 the oxygen, producing water and carbonic 

 acid gas. 



Dr. Pethick : In the act of evolution ? 



Mr. Nesbit: Yes; and if the decom- 

 posing and oxydising action of the oxygen 

 went sufficiently far, the ultimate result 

 would be nitric acid, eventually produced 



279 



from the nitrogen of the vegetable mat- 

 ter. Then with regard to the last ques- 

 tion, he must remark that he spoke from 

 practice, and not from theory alone, in 

 what he said about clover crops. With 

 respect, to the question of whether plants 

 could obtain from the air all their nitro- 

 gen, there was no doubt that some plants 

 could obtain all they wanted from the air, 

 but that others could not, at least in the 

 quantities essential to produce the abnor- 

 mal crop required by the farmer to pay 

 his rent and taxes. As to the supposed 

 abstraction of the phosphates by the clo- 

 ver from the soil, it must be recollected 

 that what was in the hay was brought 

 back again as manure, and therefore there 

 could not, under proper management, be 

 any robbing of the farm. Had he been 

 speaking of the exportation of farm-yard 

 produce the objection would be applicable; 

 as it was, it fell, he conceived, to the 

 ground. 



Mr. Geake would be glad to know 

 whether the Professor could recommend 

 any simple test by means of which the 

 farmer could ascertain for himself the pu- 

 rity or impurity of manures? 



Mr. Nesbit tnought it perfectly impossi- 

 ble to do so. The great point for the far- 

 mer was to take care that he dealt only 

 with those dealers who had something to 

 lose, that was to say, a character. (Hear, 

 hear.) He could give them no other test 

 than that. If they wished to go further, 

 they must either learn chemistry them- 

 selves, or they must entrust to others the 

 task of analyzing for them. 



M. Huxham wished to enquire of Mr. 

 Nesbit whether salt would be a good ad- 

 dition to manure, and whether it were not 

 desirable for farmers to have their soils 

 analyzed before applying artificial manures 

 to them. With regard to the breaking up 

 of clover for wheat, a friend of his had 

 told him that he had tried the experiment, 

 and the result was that for some time the 

 thing answered well, but that after a time 

 the clover died away. 



Mr. Nesbit said he believed the appli 

 cation of salt to be very useful in in- 

 creasing the strength of the straw and 

 the delicacy of the grain. There could 

 be no doubt that salt ought to be used for 

 grain crops. Even so near the sea as 

 Launceston was situated, the application 

 of three or four cwt. of salt per acre for 



