PREVENTIVE MEDICINE. 349 



Smallpox no longer claims its victims in any considerable numbers 

 except in communities where vaccination is neglected; cholera has 

 been excluded from our country during the last two widespread epi- 

 demics in Europe and its ravages have been greatly restricted in all 

 civilized countries into which it has been introduced; the deadly plague 

 of the seventeenth and eighteenth centuries is no longer known in 

 Europe and the prevalence of typhus so-called spotted or 'ship fever' 

 has been greatly limited. Typhoid fever, tuberculosis and diphtheria 

 are still with us and claim many victims, but we know the specific cause 

 of each of these diseases; we know where to find the bacteria that 

 cause them and the channels by which they gain access to the human 

 body ; and we know how to destroy them by disinfecting agents. 



The mortality from tuberculosis is constantly diminishing in our 

 large cities and the complete destruction of the infectious sputa of those 

 suffering from pulmonary tuberculosis would no doubt go a long way 

 towards the extermination of this fatal disease. 



Perhaps the triumphs of preventive medicine can not be better 

 illustrated than by a brief historical account of the prevalence of 

 bubonic plague during the past three or four centuries. It can scarcely 

 be doubted that the 'black death' of the fourteenth century was the 

 same disease which subsequently prevailed in Europe under the name 

 of 'the plague' now more generally spoken of as 'bubonic plague.' 

 While modern methods of diagnosis have enabled us to recognize 

 typhoid fever, typhus fever, relapsing fever and bubonic plague as 

 distinct diseases, it must be remembered that up to the end of the 

 fifteenth century no such differentiation had been made and the term 

 ' pest ' was applied to any fatal malady which prevailed as an epidemic, 

 and no doubt in some instances included smallpox, which prior to the 

 discovery of Jenner contributed largely to the general mortality of the 

 population of Europe. 



Bubonic plague continued to prevail in various parts of Europe at 

 the end of the sixteenth century, and early in the seventeenth century 

 (1603) an epidemic occurred in London which caused the death of 

 38,000 of its inhabitants. It continued to prevail in this city and in 

 various parts of England, Holland and Germany and six years later 

 caused a mortality of 11,785 in the city of London. During the year 

 1603 a most disastrous epidemic occurred in Egypt, which is said to have 

 caused a mortality of at least a million. After an interval of ten or 

 fifteen years, during which there was a marked diminution in the num- 

 ber of cases and the extent of its distribution in European countries, 

 it again obtained wide prevalence during the year 1620 and subse- 

 quently, especially in Germany, Holland and England. The epidemic 

 in the city of London in 1625 caused a mortality of more than 35,000. 

 In 1630 a severe epidemic occurred in Milan, and in 1636 London 



