448 Experiments upon the Potatoe, 



He adds that he does not find tall growing kinds the most pro- 

 ductive; but that they will grow in poorer soil than others; and 

 that he has obtained from soil naturally poor and light and not 

 more highly manured than for Swedish turnips, from 20 to 24 tons 

 of late Potatoes per acre. 



This is I believe the substance of the valuable Papers for which 

 the world is indebted to our President. 



In the hope of assisting in an enquiry of so much national im- 

 portance, as the determination of the manner in which the greatest 

 quantity of human or animal food can be obtained from the soil, 

 some experiments were tried in the Garden of the Society in the 

 year 1831, of which I have already had the honour to lay the 

 results before the Society*. These were principally important in 

 regard to the evidence they seemed upon the whole to afford of 

 the accuracy of Mr. Knight's views. It did not however appear, 

 from anything that had resulted from the investigation, what the 

 real difference was between the produce afforded by whole tubers 

 and common sets; and it was accordingly determined that the 

 next trial should be directed to the elucidation of that point ; for 

 although a priori, one might feel persuaded that whole tubers 

 would yield a greater produce than common sets, yet it was highly 

 desirable that this should be proved by actual experiment, for if 

 it should turn out that tubers are not more productive than sets, 

 it was clear that the cultivator would sustain serious loss by em- 

 ploying them. 



Accordingly in the year 1832 five plots of ground of equal size, 

 and as nearly as possible of equal quality, were selected for the 

 growth of five different varieties. One half of each of these plots 

 was planted with whole tubers and the other with sets containing 

 but one eye each ; the plants were one foot apart in the rows, 



* See page 143 of the present Volume. 



