508 Agricultural Chemistry — Turnips, 



and vigour of the plants or its power of appropriating the food 

 presented to it, depends upon other circumstances than the mere 

 amount of that food. 



Selected Results. 



Plot 

 Nos. 



1 

 8 

 15 



18 



22 



Description of Manures. 



12 tons farmyard-dung 



2^ cwts. superphosphate of lime, 3f cv/ts. rape-cake 

 3f cwts. superphosphate of lime, 2| cwts. rape-cake 

 20 lbs. sulphate of ammonia . * . . . 

 d\ cwts. superphosphate of lime, 84 lbs. phosphate of 

 magnesia, 75 lbs. phosphate of potass . . . 

 4:| cwts. superphosphate of lime •...«. 



Average 

 Weight of 

 Bulb. 



1-36 

 1-69 



1-75 



1-35 

 1-47 



Number of 



Plants 

 per Acre. 



15,571 

 16,096 



15,088 



19,642 

 18,446 



We see that the farm-yard dung gave a number of surviving 

 plants nearly as small as any in this series, and very far short of 

 that obtained by mere mineral, or frequently by mixed mineral 

 and organic supply. Again, the weight of bulbs is only equal to 

 the lowest resulting from pure mineral manuring, and inferior to 

 that in other cases of such manuring. In Nos. 8 and 15, on the 

 one hand, the amount of supply, especially of matter for organic 

 formations, was much less than in No. 1, whilst the average weight 

 of bulb was materially greater. On the other hand, the mineral 

 supply was in these cases less than in 22 ; but there being in that 

 instance no provision by manure of organic matter, the increased 

 mineral supply was unavailing. 



Clay and weed-ashes alone, as in No. 23, are seen to more 

 than double the unaided produce of the soil and season, to give 

 a fair number of plants, and an average weight of bulb nearly 

 three-fourths as great as in any case in the series. This is a 

 curious result, and indicates that certain mechanical as well as 

 chemical conditions of soil, in immediate proximity to the young 

 plant, are essential to a favourable and healthy development of its 

 organs of collection. We learn, too, that in some important re- 

 spects the resource of food within the soil itself could not have 

 been so low in this first year as it appears afterwards to have been. 



There are other points indicated by the results already given, 

 than those to which we have directed attention ; but as a consi- 

 deration of the experiments of the succeeding years will bring 

 them before our readers, we need not enter upon them in this place. 



Having examined in detail the results of the first year's experi- 

 ments, it may be well to reiterate some of the more general and 

 important facts and conclusions which have been elicited. It is 

 clearly shown that, under the influence of the same season, and 

 in a soil which, by corn-cropping, had been brought to that con- 

 dition of exhaustion which common usage would remedy by the 



