INFECTIOUS DISEASES. 303 



present century several severe epidemics of yellow fever occurred in 

 New York and in Philadelphia, and even as far north as Boston. In 

 the great epidemic of 1798 the mortality in Boston was 200; in New 

 York, 2,080; and in Philadelphia, 3,500. The last-named city suf- 

 fered- a series of epidemics about this time 179 7 (mortality, 1,300), 

 1798 (mortality, 3,500), 1799 (mortality, 1,000), 1802 (mortality, 

 307), 1803 (mortality, 195), 1805 (mortality, 400). The immunity 

 of these cities for many years, notwithstanding their intimate com- 

 mercial relations with Havana and other infected ports, is in my 

 opinion largely due to sanitary improvements, and especially to the 

 construction of sewers and paving the streets; also to the enforce- 

 ment of suitable quarantine regulations. 



The great epidemics in the United States during the present cen- 

 tury occurred in 1853, 1867, 1873, 1878. The epidemic of 1878 

 was the most disastrous known; 132 towns were invaded,' and the 

 mortality was 15,934 (number of cases about 74,000). 



In Europe the ravages of yellow fever have been chiefly re- 

 stricted to Spain and Portugal. This is due to the facts that meteoro- 

 logical conditions are there favorable for the development of the 

 exotic micro-organism to which the disease is due, and that these 

 countries have constant commercial intercourse with infected ports 

 in the West Indies. The first epidemic in Spain occurred in 1700 

 at Cadiz. This city also suffered in 1730-'31, 1733-'34, 1764, 

 1780, 1800, 1804, 1810, 1819-'21. The epidemics of 1800, 1810, 

 and 1819 were not limited to the city of Cadiz; the disease extended 

 to the interior, and caused a considerable mortality in the provinces 

 of Granada and Andalusia. In 1878 a limited epidemic occurred 

 for the first time in Madrid. The first Lisbon epidemic was in 1723 ; 

 the great epidemic in this city was inaugurated in 1856} and reached 

 its acme of development the following year. 



Upon the west coast of Africa yellow fever prevails principally 

 along the coast of Sierra Leone. At St. Louis (Senegal) an epidemic 

 occurred in 1778, the first of which we have any knowledge in this 

 vicinity. Frequent epidemics have occurred in Senegambia, and the 

 disease has occasionally prevailed upon the Gold coast, the Congo 

 coast, the Cape Verd Islands, and the Canary Islands. At Nassau 

 in the Bahama Islands yellow fever prevailed as an epidemic in 1861, 

 1862, 1863, and in 1869. 



Another infectious malady which, like yellow fever, has a very 

 restricted endemic prevalence is the disease known as beriberi. 

 This prevails chiefly upon the seacoast of Oriental countries, and 

 upon the islands in proximity to these coasts in the Pacific and 

 Indian Oceans. It has been imported to the West Indies and to 

 Brazil, where it prevails to a limited extent in the coast region. 



