The Bulletin 
Numerous beliefs, too, many of which are shrouded in mystery, were 
found to he entertained in regard to the causation of the disease. An 
examination of the voluminous literature on trembles and milksickness 
revealed the fact that many of these beliefs had been expressed in print, 
and that even critical investigations dealing with the etiology of the 
malady contained diverse conclusions. The one apparently most widely 
accepted by investigators, however, is that the disease is of bacterial 
origin. This opinion is contained in a recent bacteriological text-book* 
which states that the disease “is caused by the growth of and conse¬ 
quent absorption of toxic principles from the infective agent (Bacillus 
lactimorbi) lodged primarily in the small intestine and, secondarily, in 
the liver and other organs of the body.” 
In view, therefore, of the immense economic importance of trembles 
and milksickness and of the conflicting statements in regard to its 
etiology, a study of the disease was begun in the summer of 1916. This 
work was continued throughout the succeeding year and a considerable 
body of data has been secured bearing on the cause, transmission, symp¬ 
toms, and pathological anatomy of the disease. A preliminary report 
on the cause of trembles has been published,! but since the subject- 
matter of this report is included in the present paper, further mention 
of it is deferred at this place. It is deemed advisable, furthermore, 
since the readers of this bulletin may not have ready access to pub¬ 
lished accounts of milksickness, and consequently may not be familiar 
with the literature bearing on the disease, to include a considerable 
body of historical information. 
Historical Account of the Occurrence of Trembles and 
Milksickness 
This disease has for a long time been known to occur within the 
United States. Attention was first directed to its presence by a phy¬ 
sician, Dr. Daniel Drake, who published, in 1810, a brief account of it 
under the title “New Disease” in his Notices Concerning Cincinnati. 
This account, which was communicated to Dr. Drake, was based upon 
observations made in Madriver County, Ohio, by Dr. Barbee. Drake’s 
account consisted of a concise statement of the symptoms, kinds of 
animals affected, conditions favoring its prevalence, and remedial and 
palliative measures. This account was later reprinted by Drake as 
an editorial addition to an article by McCall (1830). While this note 
in 1810 is the first published account, the disease is known with cer- 
*Vide, Marshall, Charles E., edit. Microbiology, a text-book of micro-organisms, general and 
applied. 2d edition, p. 785, 1917. 
tJournal of Agricultural Research. June, 1917. 
