152 TRIAL OF SALT ON THE BEET AND THE CARROT. 



wall thicker and more solid at the same time. In either way, 

 greater strength might be attained.* 



There can be little doubt, I think, that a warmer summer 

 will usually ripen grain more thoroughly, and make it more 

 compact, harder, and heavier per bushel ; but it does not follow 

 from this that, in the same season, certain applications to the 

 soil may not also increase the comparative compactness and 

 weight. 



6. Does salt really promote the growth of the white beet 

 and of mangel- wurtzel more than the turnip ? We have seen 

 that the former, according to our present analyses, f contains 

 more salt than the latter. Will its application to these and 

 other crops be beneficial in proportion to the quantity of soda 

 or common salt they respectively contain? 



7. A similar question applies to the carrot founded on a 

 principle already explained in this work, p. 16, its alliance, 

 like the beet, to species found wild near the sea. Will salt 

 be peculiarly grateful to this plant? Or will it cause such 

 plants as the Tussac grass to grow healthily in inland situa- 

 tions ? 



Will an application of salt to such plants compensate for the 

 neighbourhood of the sea ? 



The adjustment of series of experiments always duplicate, 

 at least, and always capable of being compared with portions of 

 the same crop to which no application has been made this 

 adjustment is so simple, and there is so much room for varia- 

 tion, that I do not present any schemes for the guidance of 

 experimenters. I may only express my hope that some of the 

 topics above suggested may be taken up and submitted to rigo- 

 rous field investigation. 



* Mr Lawes considers the weight of the bushel to be determined by the tem- 

 perature. The hottest year, 1846, gave him the greatest weight per bushel ; the 

 coldest year, 1845, the smallest weight per bushel. In 1846, the bushel of the 

 unmanured space weighed 63J Ib. ; of the highly manured space, 62| Ib. : the 

 average of 36 experiments was 63 Ib. In 1845, the bushel of the unmanured 

 space weighed 56| Ib. ; of the most highly manured, 57 Ib. : the average of the 

 whole being 56 f Ib. 



f See section 4 of the preceding chapter, p. 146. 



