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legislatures offered liberal rewards for the discovery of the cause of 
the disease. In 1821 the legislature of Tennessee passed an act re- 
quiring fences to be made around certain coves in Franklin County 
“ to prevent animals from eating an unknown vegetable, thereby 
imparting to their milk and flesh qualities highly deleterious.” 
At the present time when the disease is rare many persons living 
in and near the endemic foci abstain from the use of milk and butter 
on account of the danger of contracting milk sickness. 
At the outset one is confronted with the difficulty that the affection 
under consideration is largely a matter of tradition. Satisfactory 
accounts of the disease are rare. Drake (1841), who is much quoted 
in all accounts of the disease, appears not to have been personally 
familiar with the malady; indeed in his memoir he states that he 
has seen no case in man nor in the lower animals. Yandell (1852), 
who is also frequently quoted arfd has written much on the subject, 
makes no mention of having himself seen cases, and in his later publi- 
cations expresses grave doubt as to the existence of a specific disease 
corresponding to that described as milk sickness. In his own words : 
“ Upon a review of the whole matter, the conclusion to which all the 
testimony on the subject has brought me is, that we, who have written 
upon milk sickness have been egregiously imposed upon by care- 
less and incompetent observers.” Many of the accounts, indeed I 
think I may safely say, the majority, are based upon hearsay evi- 
dence. 
A large number of the articles published on milk sickness were 
written wholly with the object of proving that a plant poison is the 
cause of the disease; many others, that a mineral poison is the 
causative agent. The disease has been described as a mild, almost 
trivial affair; and again as most malignant and fatal. A few writers 
have regarded the disease as a manifestation of malarial poisoning. 
However, the mass of the testimony clearly indicates that there is a 
specific disease, known as milk sickness, always derived from a case 
of trembles in an animal. 
Distribution . — So far as known the disease, has never occurred out- 
side of the United States. In this country it has been endemic in 
many of the newly settled regions in practically all of the States 
south of New York and as far west as Missouri and Arkansas. Ten- 
nessee, Kentucky, Ohio, Indiana, and Illinois, have suffered the most 
severely. At the present time cases occasionally occur in Tennessee 
and North Carolina. Cases have been reported in Illinois as late as 
1904. 
In the endemic foci, the disease in animals is limited to rather 
well-defined areas. Many of these areas are fenced to prevent the 
access and consequent contamination of stock. I have seen a number 
