90 



RemarJiS on the Potaioe Disease. 



Vol. XII. 



little more than the indulging' freedom of 

 thought and speculation, in a matter where 

 nature baffles us with her usual variety of 

 strange and various action. They have, 

 however, proceeded further, we believe, than 

 anywhere else, in certain practical experi- 

 ments of an important character, whose ob- 

 ject was to prove how far the potatoe, in dif- 

 ferent states of the rot, could be employed as 

 food for men or animals, without the chance 

 of producing some of those dangerous epi- 

 demics that have occasionally arisen from 

 the use of diseased vegetables. That which 

 ravaged the south of France many years 

 ago, from the use of the ergot of rye as food, 

 was a strong evidence of the hazard that 

 was run in employing vegetables in a state 

 of disease. All the experiments showed, 

 however, that there was no risk from the 

 potatoe. It fattened sheep, and it was eaten 

 cooked in the usual way, and the water in 

 which it was boiled drank with impunity. 

 We can hardly conceive this to have been 

 done, when the vegetable was in the last 

 degree of putrefaction. It would not then 

 have been a potatoe, or what we usually 

 call such, but a mass of matter, disorganized 

 by disease, and utterly incapable of affording 

 nourishment, though it might not affect health 

 or life. 



One thing is suggested by this statement, 

 that may be of practical utility, whether if 

 the crop were removed from the ground on 

 the first appearance of the disease, a large 

 part of it might not be saved. This could 

 only take place when the tubers were some- 

 what advanced towards maturity, and is 

 more likely to be possible with those planted 

 early, than the late. But the first, all ac- 

 counts seem to agree, arc less exposed to 

 the attack of this disease than the others — it 

 does not appear invariably to be so, but gen- 

 erally. The mowing of the stems at the 

 first moment of their turning black, which 

 has been recommended, and said, in some 

 reports, to have been practised with success, 

 would, we should suppose, have the same 

 effect as removing from the ground; all sup- 

 port and all connection with the atmosphere 

 being cut away, the vegetable would neces- 

 sarily cease to grow, and the progress of 

 disease be at the same time arrested. From 

 the examinations made in France, it seems 

 that the slow or rapid progress of the dis- 

 ease depends very much on the thinness or 

 thickness of the skin, or in other words, as 

 the disease is conveyed by the stem to the 

 tuber, its course will be more or less rapid, 

 in proportion to the strength of the material 

 through which it has to make its way. This 

 may be a reason why some varieties are 

 more liable to the attack and ravages of the 



rot than others, which appears uniformly to 

 be the case in Europe and in this country. 

 Here the Mercers are said to have been 

 more seriously affected than any other. On 

 the farm of the writer, a variety brought 

 from the State of Maine, and which had 

 only been planted one year in this climate, 

 were equally injured with the Mercers. 

 These are, however, some of those facts 

 that are often found to contradict every gen- 

 eral statement, and which we can only sur- 

 mount, by taking the tendency of the whole 

 evidence. 



After as full an examination as we have 

 been able to make, it appears to the writer 

 that the source of this rot may be considered 

 as depending on the condition of the seed 

 and the state of the atmosphere, the one 

 possessing a delicacy and liability to disease, 

 and the other by its ungenial nature, devel- 

 oping them. If we could be entirely satis- 

 fied that the disease in the tubers arose 

 solely from the diseased condition of the 

 stem, and that this was owing to atmosphe- 

 ric changes alone, then the cause might be 

 considered as determined, and the whole 

 matter would be nothing more than a ques- 

 tion as to when these influences would cease. 

 But there are many instances recorded, in 

 which the tubers were diseased, while the 

 stem and leaves remained fresh and green; 

 and in such cases we are compelled to re- 

 gard the tuber, as from some cause, being in 

 an unhealthy or delicate state. But notwith- 

 standing the strength of the argument in 

 favour of these atmospheric changes being 

 the source of the disease, and they certainly 

 seem the most plausible way of accounting 

 for it, yet we cannot bring ourselves to as- 

 sent to it in its full force, but think that they 

 rather tended to develope disease in a vege- 

 table already made delicate and predisposed 

 to morbid action. In Sweden, where the 

 rot existed, instead of these ungenial vicis- 

 situdes of temperature, the summer was re- 

 markably dry; and in parts of South America, 

 near the original home of the potatoe, a dis- 

 ease that on examination seems identically 

 the same with that prevailing here, is not at 

 all uncommon. The fungi, insects, &c., ob- 

 served in the tubers, we regard not as the 

 original source of disease, but as some of 

 those means nature uses to bring about those 

 changes and transformations that are inces- 

 santly going on in matter. 



A. L. Elwyn. 



Philadelphia, Oct. 5ih, 1847. 



Wheat, oats, rye, Indian corn, potatoes, 

 hay and tobacco, are raised in every State 

 and territory in the Union. 



