HISTORY 



1365 



ophthalmo-diagnostic method. The diagnosis of a mixed infection 

 has been rendered easier by the absorption test as introduced 

 by Castellani in 1902, which is of use also in the determination of 

 closely allied bacteria. The B. typhosus has been found to be 

 capable of living for weeks in the spleen, and for years in the gall- 

 bladder, of people who are designated ' typhoid-carriers,' as the 

 bacilli escape in the faeces in the latter case. The bacilli have been 

 shown to occur naturally in water-supplies, earth, dust, fomites, 

 flies, shellfish, and milk, etc. The subject of relapses has been 

 studied by Chant emesse and Widal in 1892, Wright and Lamb in 

 1899, and Durham in 190 1. 



Attempts to obtain an antityphoid serum by Macfadyen, Hewlett, 

 and Chantemesse, have not been successful, but Wright and Semple 

 devised a vaccine in 1897 which was perfected by Leishman, and 

 has been much used and has rendered great service; later Castellani 

 brought forward vaccination with a mixed typhoid + paratyphoid 

 A -f- paratyphoid B vaccine dead or living (attenuated) as a method 

 of prophylaxis, while more recently Besredka and Metchnikoff have 

 advised a living, not attenuated, sensitized vaccine. 



The subject of variation of the B typhosus has been studied by 

 Twort, Horrocks, and Penfold. 



In 1895 Gilbert gave the name ' para-colon ' to bacilli occupying 

 an intermediate position between B. coli and B. typhosus. In 1896 

 Archard and Bensaude used the term ' paratyphoid ' as a name for 

 such organisms when capable of producing the symptoms of enteric 

 fever, but this name dropped into oblivion, only to be revived 

 by Schottmiiller in 1901, when he clearly demonstrated his B. 

 paratyphosus A and B. paratyphosus B as the cause of two forms 

 of enteric fever, the diagnosis of such cases being obtained by the 

 specific agglutinative reactions, or, better, by cultivation from the 

 circulating blood. This is the reason why the symptoms charac- 

 teristic of enteric fever are ascribed to three allied organisms — viz., 5. 

 typhosus Eberth, B. paratyphosus A Schottmiiller, and B. para- 

 typhosus B Schottmiiller. 



The presence of typhoid fever in the tropics has, even in recent 

 times, been much debated, and apparently the view has been held 

 that it was overlooked by the older tropical physicians. This, 

 however, is quite erroneous, for typhoid fever was early recognized 

 in the tropics after its separation as a clinical entity by the workers 

 in the Temperate Zone. Thus Scott and Milley, in 1830, showed 

 that it existed in Tasmania; Levacher, in 1840, in St. Lucia; while 

 it was recognized in 1841 on the Niger River, in West Africa, and 

 in Martinique, and somewhat later in Sierra Leone and Gaboon. 

 In 1842 an epidemic is mentioned as occurring in Rio di Janeiro 

 m Brazil, and others in Tahiti in 1847, 1849, i853~54' ^^^^ 

 Damascus in 1852, and in Cayenne in 1852-53. Other epidemics 

 were recorded in Cuba in 1853-54, while in the latter year Scriven 

 definitely proved its existence in India by demonstrating the 

 ^■vphoid ulcers found by post-mortem examination. In the same 



