INFLUENZA IN HORSES. 203 



action of light aud air on tbcm, the tubers vvill not attain a healthy and 

 consolidated growth, aud the use of such for seed will increase the ten- 

 dency to premature decay, and to the attacks of the potato "fungus, 

 Botrytis infcstans, which is always present in damp places on plants of 

 the natural order solanecc, but never on any plant not of that order. 



The mechanical and chemical properties of the soil in which potatoes 

 are planted should be also considered. Potash has the property of ab- 

 sorbiug and retaining moisture in a high degree, and will thereby tend, 

 when present in excess, to keep it wet or moist, while carbonate of soda 

 has the property of giving oft water, that is, in a dry atmosphere. Soda 

 effloresces ; its crystals will lose in a dry atmosphere the greater part of 

 their water on mere exposure to the air. These conditions should be 

 especially considered when either of these alkalies is in excess in the 

 soil, particularly when a soda soil is in contact with a very moist one; 

 since they may have important effects not onlj' on the chemical condi- 

 tions of the potato but also on the growth of the relative proportions of 

 the organic structure, such as tlie spiral ducts, parenchyma, nitrogenous, 

 and starch cells. 



The ash of potatoes which grew on a potash soil, according to Pro- 

 fessor J. \\. Harding, of Virginia, contains potash 53.5, soda .5. During 

 the month of December last we liad an opportunity of making a par- 

 tial analysis of some samples of potatoes grown upon soil strongly 

 impregnated Viith soda, (sent to this Department by W. F. Arney, 

 secretary and actiug governor of New Mexico,) and it was found that 

 there was a strong jn-edominauce of the amount of soda present over 

 that of the i)otash, showing the power of substitution, and suggesting 

 the possibility of change in cellular structure in consequence. 



I would recommend that when tubers in any locality have grown to 

 a state of perfection during epidemic periods, as in the case of the Jackson 

 Whites alluded to, a sufficient quantity of such should be selected for 

 seed purposes and planted in still more favorable localities, and that 

 this course should be continued. 



INFLUENZA IN HORSES. 



Bv Ja:\ies L.v^v, 



Professor of Veterinary Sc'tcncei*, Cornell Universltij. 



In presenting the following report on influenza, I beg to acknowledge 

 iny indebtedness to correspondents of the Agricultural Bureau for 

 valuable information concerning the i^rogress of the malady, and also 

 to the various scientific men mentioned in the text, who have all re- 

 sponded promptly and heartily to any request for information or assist- 

 ance. 



While much that is of value has been secured, and especially on the 

 question of the causation of the disease, I would respectfully submit 

 that certain pouits require further investigation, and are yet capable of 

 elucidation, inasmuch as the malady is still progressing and continually 

 invading new territory. 



I would refer especially to the observations on the amount of ozone 

 in the air, and the disturbance of atmospheric electricity, both of which 

 were remarkably in excess at Toronto in September, and the former at 



