414 CATTLE. 



an area of one hundred acres, whilst for a considerable distance 

 around it is not produced. Thus having the locality perfectly cir- 

 cumscribed, much labor has been expended in order to discover some 

 production peculiar to the locality. The search has been uniformly 

 unsuccessful in the attainment of its object. The general appearance 

 of these infectea districts is somewhat peculiar. I have always 

 observed that the situation of the ground is elevated above that of 

 the surrounding country, occupying what is denominated a ridge, and 

 that the quality of the soil is in general of an inferior description. 

 The growth of timber is not observed to be so luxuriant as in situa- 

 tions otherwise similar, but is scrubby, and stunted in its perfect 

 development. Throughout the entire district in which these localities 

 are interspersed, there is observed an absence of the occurrence of 

 stones scattered over the surface, whilst in the infected districts, they 

 are almost universally present. They are of small size and darkened 

 aspect externally, breaking with a regular and shining fracture, and, 

 upon analysis, imperfectly made, were found to contain a considerable 

 portion of iron, with slight traces of copper. Another more decided 

 and peculiar appearance, which serves to distinguish them from other 

 spots, is the breaking forth of numerous feeble springs, furnishing a 

 trifling supply of water, but not varying in quantity with the change 

 of seasons. In its appearance, it presents the general evidences of a 

 sulphurous and ferruginous contamination. 



Experiments made upon the water collected from these springs, or 

 more properly called oozes from the soil, with the greatest care, by 

 the employment of the most delicate chemical re-agents, failed to 

 indicate the presence of any mineral except iron, sulphur, traces of 

 magnesia, and a quantity of copper barely capable of being demon- 

 strated. A belief being entertained by many that the disease is occa- 

 sioned by arsenic, or some of its salts, I, with much care and patience, 

 subjected not only the water, but likewise the earth, from these dis- 

 tricts to a most rigid examination, and by no test was I furnished with 

 the slightest evidence of its presence. 



An intelligent medical friend expressed to me his belief, that it was 

 produced by the inhalation of some noxious gases generated during 

 the night ; in proof, he stated that he had observed cattle, which 

 were regularly housed each evening, escaped its attacks, and that 

 when suffered to remain at large, they were frequently seized with 

 the disease. It is difficult to form this belief of the nature of the 

 cause, as we can hardly conceive the particular action of any com- 

 bination of circumstances, capable of giving rise to such an emanation 

 only at night, ceasing to operate during the day. The most popular 

 belief is in favor of a vegetable origin. But this appears irrecon- 

 cilable with the fact that the disease has frequently appeared with 

 its greatest virulence when the grounc. has been for weeks previously 

 covered with snow. 



