X INTRODUCTORY NOTE. 



epidemic and contagious diseases has yet to be made 

 out; 



This shows that at the time here referred to the 

 Germ Theory, in its wider medical sense, had begun to 

 ferment in England. Two years, indeed, prior to the 

 above occasion, and for the use of the same Association 

 as that addressed by Mr. Wells, the late Dr. William 

 Budd had drawn up a series of ' Suggestions towards a 

 Scheme for the Investigation of Epidemic and Epizootic 

 Diseases,' which strikingly illustrate the insight of a 

 man of genius, withdrawn from the stimulus of the 

 metropolis, and working alone, at a time when the 

 whole medical profession in England entertained views 

 opposed to his. Budd states in succession, and with 

 perfect clearness, the points which he considers most 

 worthy of the attention of the Association. He re- 

 commends inquiry as to the nature of the evidence 

 alleged to prove the disease under investigation to be 

 contagious or communicable. Whether such disease 

 admits of being artificially propagated by inoculation 

 or otherwise. Through what surface or surfaces the 

 virus may be shown to enter the body, and to leave it, 

 when the disease is taken in the natural way. Whether 

 the disease is distinguished by eruptions external or 

 internal. Whether it has a period of true incubation; 

 and if so, what are the length and limits of that period. 

 Whether one attack, as in smallpox and many other 

 contagious diseases, preserves against future attacks. 

 Whether in the case of human disease animals as well 

 as man are susceptible, and if so, what animals. What 

 is the evidence, if any, as to the particular country or 

 region in which the disease first appeared. What are 



