1889.] PUBLIC DOCUMENT — No. 4. 533 



Plat 2. The scabby seed potatoes were allowed to remain 

 for twenty-four hours in a saturated solution of muriate of 

 potash before being planted. 



Plat 3. A strong solution of hypochlorite of lime (bleach- 

 ing lime) was applied in a similar way, for the preparation 

 of the scabby seed, as in case of plat 2. 



Plat 4. A saturated solution of carbolic acid in water 

 sei'ved in this instance for the treatment of the scabby po- 

 tatoes. 



The potatoes were planted in all plats on the same day. 

 May 7. The vines did not appear evenly at first ; they were, 

 however, equally vigorous upon all plats at the close of June. 



The tops on all plats were pretty generally dried up 

 August 8. The potatoes were harvested on the entire field 

 August 30. The yield on all plats was fair, and the quality 

 of the potatoes, almost without exception, excellent ; this 

 seemed to be more striking in regard to those on plats 2, 3 

 and 4, which had been, in the beginning of the season, some- 

 what behind in growth. Here and there could be seen a 

 potato with a small mark of scab ; a large proportion were 

 perfectly smooth, and without any sign of it. The results 

 were recorded as those of a first experiment. 



The fact that a scabby potato may produce, under certain 

 circumstances, a smooth and otherwise excellent potato, 

 was confirmed. Good potatoes have been raised before 

 from seed potatoes sufiering from scab, without any previous 

 treatment similar to ours. Without any intention of antici- 

 pating the results of future observations, or to point out 

 with certainty the exact cause of our results, we expressed 

 the opinion that a difierence in the condition of the soil in 

 our old and new experimental potato plats might have 

 proved to be the principal cause of our trouble ; for the 

 former yielded, from healthy potatoes, most inferior scabby 

 potatoes ; while the latter produced, from scabby potatoes, 

 a most superior, smooth potato, under otherwise almost 

 identical conditions, as far as soil, mode of cultivation and 

 kind of fertilizer were concerned, upon lands in close prox- 

 imity, during the same season. 



