APPENDIX E. cxxxix 



with places already affected succeeded in protecting a country 

 from its invasion/ Out of the area in which it habitually 

 exists as an endemic disease, malignant cholera does not 

 seem to be directly generable ' by any known or appreciable 

 conditions of local insalubrity, however much these conditions 

 may favour its development or aggravate its intensity when 

 it is once present, or is close at hand.' The spread of the 

 disease from its endemic site seems undoubtedly to be in- 

 fluenced by obscure atmospheric or other unknown conditions, 

 comprised under the term ' epidemic influence/ Sir William 

 Jenner asks: 'What is the specific cause-relation between 

 cholera and choleraic diarrhoea, and between severe summer 

 diarrhoea and choleraic diarrhoea ? Is cholera, in the form 

 of choleraic diarrhoea, always amongst us ? ' And Mr. Mac- 

 namara, in part, replies from Calcutta that ' cholerine is 

 simply a modified form of Asiatic cholera, and is capable of 

 engendering this more deadly form of the disease in other 

 people by means of the dejecta/ He says, also : ' I know 

 that several of the leading practitioners in this part of India 

 are of opinion that cholera is " a something generated in the 

 bodies of those attacked by it, quite independently of all 

 external influences V ' 



Turning now to such affections as influenza and mumps, 

 these also are diseases which present various degrees of 

 contagiousness, and are frequently epidemic in their mode of 

 onset. Both are believed to be capable of arising de novo 2 , 



1 'A Treatise on Asiatic Cholera,' 1870, p. 327. It is only fair to 

 add, however, that Mr. Macnamara does not give his assent to this view. 

 He is a firm believer in the communicability of cholera. He admits 

 that ' sporadic cholera ' is easily generable de novo, and that ' cholerine/ 

 from which it is often quite indistinguishable, is capable of giving rise 

 in others to malignant cholera ; and yet he wishes to maintain the dis- 

 tinctiveness of the latter form of the disease. But other affections also 

 exhibit different degrees of contagiousness, and it would seem to us that 

 ' sporadic cholera,' which is easily generable in certain parts of India, 

 cannot really be distinct from ' cholerine.' 



2 Dr. Morris says ( Germinal Matter and the Contact-Theory,' 1867, 



