Transactions of Ihe LiOndon Horticultural Society. 415 



the hottest part of his flues; but, I think, not without some ill consequences. 

 His machinery is a good deal superior to mine, and his skill and science in no 

 degree inferior ; but his melons, though very large, and apparently perfect, are 

 generally much surpassed by mine in richness and flavour. When sulphur is 

 made to evaporate, some uncombined acid flies oflP, and this Mr. Williams 

 suspects (and I agree with him in opinion) to operate injuriously upon the 

 health of his plants. It seems probable that the same uncombined acid would 

 cause the flowers of sulphur to operate injuriously; but, though I have often 

 applied it in large quantities, I never witnessed any ill effects." 



22. MeteorologicalJournal, SfC.,for the Year 1836. By Mr. Thompson. 



23. Ayi Account of some further Experiments made in the Garden of the Sodeti/, 

 in the Year \ 836, relative to the Cultivation of Potatoes. By Mr. Robert 

 Thompson. Read December 6. 1836. 



This paper, as containing not only original experiments made in 1836, but 

 a summary of all those made in 1831 and 1832, is by far the most valuable 

 that has appeared on the subject of the Potato in these Transactions. 



" In the year 1831, experiments were made with the view of ascertaining the 

 effect of planting the sets of potatoes much wider apart than usual, in order 

 to give the foliage a greater exposure to light. Whole tubers were accord- 

 ingly planted in spaces containing 16 sq. ft. The result was, that strong- 

 growing sorts, including a number of Mr. Knight's seedlings, produced fully 

 an average, whilst a few gave a very great crop. But although one of the 

 latter produced at the rate of 21 t. 13 cwt. 59 lb., a weak-growing sort pro- 

 duced only 1 t. 5 cwt. 92 lb. The vigorous could avail themselves of their 

 ample space, which they occupied with their stems and foliage to the full 

 extent ; the weaker could not. Hence the propriety of suiting the distance 

 of planting to the vigour of the sort. [See p. 396.] 



" In the year 1832, experiments were made with regard to the relative pro- 

 duce of sets from whole tubers, and from single eyes. The result was in 

 favour of the latter by upwards of 7 cwt. per acre, and considerably more on 

 comparison of the clear produce after deducting the weight of sets employed 

 in both cases. [See p. 347.] 



" The trials of 1831 gave rise to further experiments with regard to the 

 space between the sets. Accordingly, in 1834, another experiment was made, 

 for the purpose of ascertaining the most preferable distance at which the sets 

 of commonly cultivated varieties should be planted ; and at the same time a 

 repetition was made of the comparison between whole tubers and single eyes. 

 The distances between the rows were 2^ ft., 2 ft., li ft., and 6 in. The re- 

 sult with regard to distance was, that the crop was found to be greatest 

 where the distance between the rows was most in accordance with the height 

 of the stems ; and the most uniformly abundant produce was from rows 2 ft. 

 apart. The comparison between whole tubers and single eyes was still found 

 to be in favour of the latter. 



" The experiments in the present season [1836] have been made with re- 

 gard to 



" First, the time of planting ; first week in March, and first week in April. 



" Second, the sets ; whole tubers, bases, and points of tubers. 



" Third, the depth ; 3 in., 4 in., 6 in., and 9 in. 



" A piece of ground in the kitchen-garden, which was previously in grass, 

 was trenched and planted with the bread-fruit potato, a sort which for pro- 

 ductiveness is, perhaps, unequalled near London by any other of so fine a 

 quality. The ground was divided very exactly into six equal parts. Three 

 of these were planted respectively with whole tubers, bases, and points of 

 tubers, in the first week in March ; the other three compartments in a similar 

 manner, in the first week in April. The following table exhibits the results, 

 calculated for an acre : — 



E E 4 



