xxviii Introduction. 



tions of these visitations ; for we find facts grouped according to their 

 atfinity in the series of cause and etfect. This scientific method of 

 transmitting what should be known of the history and nature of animal 

 diseases to future generations, was inaugurated by the Italian physician 

 Ramazzini, who undoubtedly laid the foundation for accurate observa- 

 tion in this department of veterinary science. And to this philosopher 

 history is indebted for much that is known of one of the greatest 

 epizooties of modern days. From that time to the present, maladies 

 of this class have been neither few nor far between 3 but observers 

 have rapidly increased in number, and in proportion as these have at- 

 tained the scientific proficiency i:iecessary for such a ditficult study, so 

 have the nature of animal plagues, and the measures needed for their 

 mitigation and prevention, become better known. 



A detailed description of all the epizootic or panzootic diseases which 

 have occurred would occupy far too large a space, and might not after 

 all be a very useful study 5 those occurring within the last two or three 

 centuries, however, deserve much attention, as competent men have 

 exerted themselves to discover their origin, trace their affinities, define 

 their characteristics, and, best of all, to modify or avert their desolat- 

 ing influences. A record of epizootic diseases founded on history 

 and accurate observation, cannot tail to be a work of great importance 

 to medical science and to civilization. Nothing can be more useful 

 than to possess the most exact details as to the character, progress, 

 duration, and termination of these maladies, and especially if our 

 knowledge of pathological changes of structure be brought to bear 

 in observing and describing the organic lesions effected by them. 



The comparative pathologist can no more aflbrd to dispense with the 

 history of diseases, than the healer of mankind, especially those of a 

 general character j for in proportion as he knows the past, he is in a 

 better position to control the present, and make provision for the future. 

 As an eloquent writer remarks, when about to describe an epidemic dis- 

 order whose cause was very obscure : ' No single generation of medical 

 practitioners can be expected to possess a sufficient range of observation, 

 or to accumulate adequate materials of information on the subject, to 

 enable them to detect the clue by which to thread the intricacies of 

 this inquiry. The past must be scrutinized, and its reflected light 

 brought to our aid 5 old and new facts when collated, by the harmony 

 which they exhibit, become mutually illustrative, and acquire a value 

 previously unknown. It is true, that medical records abound in falla- 

 cious and imperfect observations, transmitted from one generation to 

 another, and that popular prejudices have exercised an influence in dis- 



I 



