Experiments in Physiological Botany. 253 



In my next letter, I shall probably describe what we call 

 town gardens, which answer to your Kensington Gardens, 

 and to the Phoenix Park, in Dublin. 



I am, Sir, &c. 

 Pfaueninsel, Feb, 20. 1829. G. A. Fintelmann. 



Art. IV. An Account of some Experiments i)i Physiological 

 Botany, undertaken at Welbech in 1823-24, and repeated in 1825, 

 with a View to ascertain the probable Cause of Failure in Early 

 Forced Grapes. By Mr. Joseph Thompson, Gardener to His 

 Grace the Duke of Portland. 



Sir, 



In December, 1823, and January, 1824, I placed some 

 vines in pots at the front of a low Calcutta pine-stove, and 

 inti-oduced the tops of the vines into the stove, through the 

 9-inch brick wall, one near the entx'ance of the fire-flue, and 

 the other more distant from the fire, stopping the wall with 

 moss, and protecting the roots from frost with stable litter in 

 the usual way. I examined them every day, and on the 12th 

 or 13th day (I made no notes that year) I found them be- 

 gin to vegetate at the top buds ; I then wounded them in 

 different places daily, and found the sap descend in regular 

 progress from the tops to near the front wall ; when that near 

 the fire-place began to wither, the first shoots became curled, 

 downy, and quite stagnant, the other vine did the same in a 

 day or two after. Those vines did not recover, nor were in 

 health at the tops all summer ; but some shoots came out 

 near the surface of the pots in the first week of April, which 

 were very healthy, and 5 or 6 ft. high before the autumn. 



I then determined to change the usual practice, in the first 

 operations of the early forcing the next season, and resume 

 those and other experiments with greater precision by taking 

 notes, &c. 



In January, 1825, I selected two strong vines, and cut 

 them down to 5 ft. 6 in. high, the wood was firm and good, 

 they were re- potted into full-sized peck-pots, leaving the balls 

 entire for daily inspection. 



On the 24th of January, these vines w^re placed in the 

 same places as those mentioned in the last year's experiments : 

 that nearest the fire-place was only protected from frost in 

 the usual way, without paying any regard to roof and rain- 

 water ; the other was protected from roof and rain-water 

 by a larger quantity of manure in a state of fermentation. 

 Both vines reached full 4 ft. within the stove, which contained 



