98 QUARTERLYJOURNAL. 



My microscope being made by myself, is of course very inferior 

 to those now manufactured in London and Paris ; and it would be 

 very desirable that some of our scientific societies would import 

 one of these, the cost of which is too high for persons of moderate 

 incomes. It might be made accessible, under certain conditions, to 

 those desirous of undertaking such investigations as these ; for there 

 are many cases where the action of various substances on the causes 

 of animal and vegetable disease are examined to very great advan- 

 tage under the microscope, and effects seen which cannot be ob- 

 served in any other way. 



Should any gentleman, possessed of one of these superior instru- 

 ments, be desirous of examining this disease, I would request of 

 him to look at the action of the sulphate of iron, sulphate of soda, 

 or of ammonia, or of any other substance which can be cheaply 

 applied to the soil as a preventive, and to give notice of his obser- 

 vations either in your or some other periodical, for I see with 

 delight anything that can bring nearer to each other science and 

 agriculture. Yours, 



J. E. Teschemacher. 



Boston, Oct. 1844. 



NUMBER TWO. 

 To the Editor of the N. E. Farmer— 



Not having seen any communication objecting to the views I 

 have taken of the cause of the disease in the potatoe, and which 

 subsequent examinations have only tended to confirm in my own 

 mind, I resumed the investigation of the subject. The results I 

 now offer to you for publication. I have first to notice the idea 

 that this disease arises from worms which are found in the decayed 

 potatoe — and remark, 



1st. That the worms are the same which are found in all rotten 

 potatoes, from whatever cause the decay may arise. 



2d. The potatoe decays previous to the worms appearing, for 

 the worms are never found in the sound part of the potatoe, eating 

 their way in or depositing their eggs, nor have I ever seen the 

 worms in that part of the potatoe in which the fungus has already 

 commenced vegetating : it is only in the most rotten part that the 

 worms exist, after the fungus has caused this decay. 



