198 Cause of the Potato Disease. [Oct., 



fer more from atmospheric influences than those that are unma- 

 nured and have grown rather slowly, upon a dry sandy soil. 

 Vigorous plants have more generally escaped the rot than the 

 feeble. We mean those of a hardy constitution. We remark 

 again that probably if the disease of the potatoes is caused by at- 

 mospheric influences, we shall discover signs of those influences 

 on o !ier ve etables; and if potatoes are diseased and kept dry 

 after the disease has commenced, its progress is stopped, at least 

 in many instances, as we have witnessed. 



A mystery which overspreads the subject before us is the fact 

 that some varieties which appear quite exempt from the disease, 

 in some places, does not hold good in others. At first view it 

 seems that the same variety ought to hold out at all times and 

 places against the enemy. But it may be after all that varieties 

 like species require a particular soil to raise them to a high 

 standard of excellence. For instance, one variety attains its 

 standard of perfection in a light soil only, whereas another variety 

 requires a strong clay soil. They are secure from disease only 

 when they are cultivated upon that soil which they require, to 

 reach their mark or standard of perfection. Now some varieties, 

 like some species of plants, are not sofastidiuos in their food, and 

 hence do well if they have but a middling chance. The merinoes 

 or long reds seem to be of this class. However all this may be, 

 it is an important inquiry what soil is best suited to a^ given va- 

 riety of potato. We know that some apples, the Newtown pippin 

 for instance, must have a deep strong soil, and comes to nothing 

 when planted in a poor soil. And why should there not be the 

 same variety in the habits of varieties of potatoes as in apples and 

 other fruits. 



If then the above is a rational view of the fact, it will proba- 

 bly be supported by observation. The first question to settle 

 after it is known that some varieties are more aflfected than others 

 is, what kind of soil do they require, or what is the best soil 

 to give them the perfection of the variety. Observations have 

 been made upon potatoes in mass, so far at least as it regards the 

 disease, as it has appeared upon different kinds of soil. One 



