AMERICAN INSTITUTE. 77 



From another letter, written by Dr. Hosea Fountain, of Yorktown, (no 

 State named,) upon the subject of potato disease, Mr. Robinson made 

 some extracts, showing the Doctor's opinion, that other vegetables are 

 affected by the same cause that produces the rot in potatoes, as he had 

 observed when the potato tops turned black, that cabbage, onions, ruta- 

 bagas and carrots have been killed, and grapes and cherries affected by the 

 same atmospheric influence. Potatoes raised from seed balls rotted just as 

 bad as older sorts ; and he thinks the disease always commences in the 

 tops, and comes all of a sudden, and if severe enough to kill them at once, 

 so as to stop the circulation, the tubers may escape, as they do when the 

 diseased tops are mowed off. XJnfermented manure produces late growth 

 of vines, and this as well as wet ground and late planting, leaves the vines 

 green and liable to the influence that kills the tops and rots the roots. As 

 preventives, the Doctor recommends seed of hardy varieties, planted early 

 on dry ground, hilling-up to shed rain, and sowing lime, sulphur and chlo- 

 rine on the tops. Swamp muck used as manure has proved advantageous. 

 After the top is struck with disease the only safe easy remedy appears to 

 be in mowing the tops. The Doctor urges experiments based upon the 

 theory that the disease is, like the cholera, an atmospheric one, and 

 may be prevented by similar means — disinfecting the air, and plants when 

 attacked, and guarding against disease producing causes. 



The President. — There is no difiiculty, at least I have found none, in 

 raising potatoes free of disease, when the ground is properly prepared. I 

 contend that to grow good potatoes, all land requires under-draining and 

 plowing 20 inches deep, and then planted with cut seed, and the land 

 limed, the potatoes will not rot. I am planting 500 bushels this year, and 

 I shall be surprised to find ten rotten potatoes. I always rub off sprouts, 

 but I plant those sprouts and got good tubers, and I believe if any man 

 has the disease upon his farm it is his own fault. 



INDIAN CORN. 



Mr. Lawton read a letter from Mr. A. Granger, of this city, who says 



he reads the reports of the meetings with great pleasure, and writes some 



facts that he has learned about late planting corn. He said that a field 



cut off by worms was planted in Michigan, June 23, which produced the 



best crop in the neighborhood. Mr. Lawton said that intimately connected 



with this subject is the temperature of the weather. Here is a tabic 



extracted from records kept by Delatour in this city, which gives the 



aggregate average temperature of the first fifteen days of May, since 1849, 



which, being divided by fifteen, gives the average of the temperature of the 



same period in each year, which shows at a glance how one year compares 



with another : 



TABLE of average temperature of the first fifteen days in May. 



1849. 1850. 1851. 1852. 1853. 



Aggregate averages, 718 775 786 782 768 



Average of fifteen days, 48 51 § 52^ 52 51 



1854. 1855. 1856. 1857. 1858. 



Aggregate averages, 754 739 708 752 840 



Average of fifteen days, 50^ 49^ 47 50 54 



