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XXIV. The result of some Experiments on the Growth of Potatoes, 

 tried in the Garden of the Society in the year 1831. By John 

 Lindley, Esq, F. R. S., Assistant Secretary. 



Read November 15, 1831. 



In the Seventh Volume of the Society's Transactions, page 405, 

 there is a highly important Paper by Mr. Knight upon the culti- 

 vation of the Potatoe, in which he has showed that the usual mode 

 of treating that plant is by no means such as is best calculated to 

 ensure the greatest produce ; and that by taking care that full- 

 grown tubers are used for seed, and that all the foliage is fully 

 exposed to light and air, a crop much larger than had previously 

 been supposed possible can be procured with certainty. After 

 detailing his mode of management Mr. Knight states that in one 

 case he obtained 18 tons 14 cwt. 70 lbs. and in another, 24 tons 

 6 cwt. 98 lbs. from an acre of ground. This so much exceeded 

 every thing that had previously been heard of, crops of Potatoes 

 varying from four to twelve tons an acre, and never exceeding the 

 latter weight, that doubts were by some entertained of the exact- 

 ness of Mr. Knight's conclusions ; so that, although any person 

 well acquainted with the laws of vegetation would have understood 

 that the result was no more than might have been expected, yet 

 for the sake of producing further evidence of the fact, it was 

 thought desirable that some enquiry into the subject should be in- 

 stituted in the Garden of the Society. 



Accordingly, at the desire of Mr. Knight, twenty seedling varie- 

 ties of the Potatoe raised by himself, were made the subject of an 

 experiment. A single tuber of each was accurately weighed, and 

 then planted in the centre of a piece of ground four feet square, 



