MB. TOWERS ON THE POTATO DISEASE. 



33 



little decay of the tubers in September, and their quality was 

 very good. This experiment proves that " self-sowing," as it is 

 termed, is no security from disease of the leaf at least. In an- 

 other instance, one large solitary plant had died away completely, 

 and became a pale buff. I digged the potatoes, and found a 

 great return. One only was tinged with the reddish corrosion 

 so much resembling that which is seen in the bruised pulp of an 

 apple. 



So fine were these potatoes, that about the 1st of October I 

 had a row of more than 10 yards planted with the entire smaller, 

 or the halves of the larger tubers. 



3. During the course of April all my potatoes were planted ; 

 and, whether entire or cut, the tubers were coated with dry lime 

 before they were placed in the ground, and more lime was 

 sprinkled over them before they were covered with earth. In 

 the month of August, whatever the situation or the variety, the 

 leaves of all became affected. In one instance the haulm was 

 cut off within 9 inches of the surface, in others it was left un- 

 touched, but I could perceive no difference in the results. Some 

 tubers (yet comparatively few) became spotted, others a mass of 

 brown watery pulp, but of most the quality was, and remains, 

 good. 



The inferences I draw are these : — No security has been ob- 

 tained by any precautions adopted by me or by others with whom 

 I have conversed. 



4. The old store was finally inspected in April, when some 

 gallons of diseased tubers were remored, and, with a quantity of 

 sproutings and some damp straw, were thrown in a heap near a 

 ditch. There, after a few weeks, numbers vegetated, formed a 

 mass of luxuriant verdure, and those plants remained long free 

 from taint. At length they fell over, and died away, when it 

 was found, by inspection of the mass, that only a very few tubers, 

 none so large as a walnut, had been produced — proving that de- 

 cayed vegetable matter, without any of the proper earths, was 

 entirely insufficient to support potatoes. Peat or heath soil from 

 Bagshot I have proved to be a most fertilizing medium ; but 

 though from one four-ounce tuber I had twenty-eight returned 

 (some much larger), yet the quality as to flavour was not satis- 

 factory : hence it should appear that loam is required to support 

 the tuber. 



5. The period of planting appears to possess some influence : 

 thus, within half a mile of my residence, there is a field of several 

 acres which I remarked in passing to be perfectly green and 

 healthy on the 17th of September. I saw it again a month after, 

 and perceived no change. The foliage appears to have escaped 

 infection, perhaps from the late planting, which was not made 



VOL. II. D 



