336 SCIENCE PROGRESS 



" Mais si, au contraire, le mal tient au developpement d'un parasite dont le germe 

 est si extraordinairement rdpandu qu'il est impossible d'y soustraire le terrain de 

 culture, ne vaut-il pas mieux, au lieu de l'extirper sans cesse, agir sur le terrain 

 meme et le rendre impropre au developpement du parasite ? 



" Envisagee sous cette forme, la lutte contre la tuberculose trouverait peut-etre 

 a. gagner. La medecine reconnait deja chez les individus arthritiques des 

 circonstances defavorables a devolution du bacille de Koch. N'est-ce pas le 

 moment d'etudier quelles sont ces circonstances, de chercher s'il n'y a pas la, au 

 fond, quelque cause d'ordre chimique, quelque chose qui rappelle l'un des bouillons 

 de tout a l'heure vis-a-vis de la bacterie du sorbose ? " — G. Bertrand (1906). 



The Mechanism of Infection in Tuberculosis 



A notable extension of the Public Health Act of 1875 made in 

 May 191 1 renders the notification of pulmonary tuberculosis, 

 when diagnosed in hospital in-patients, a statutory obligation. 

 By an extension of this Order the notification of all cases of 

 pulmonary tuberculosis whenever and wherever diagnosed is 

 now recommended. 



The Insurance Act, 191 2, with the terms of which most 

 people are tolerably familiar, makes provision for the treatment 

 of such cases in hospitals and goes so far as to provide for 

 the actual isolation of persons suffering from pulmonary 

 tuberculosis. 



It is admitted by most observers that tuberculous infection, 

 at least in adults, is the result mainly of invasion by way of 

 inspired air of the respiratory tract ; but it is equally well 

 known that the tubercle bacillus may gain entry by other 

 means. Milk contaminated with bacilli from tuberculous cows 

 and the flesh of animals which show evidence of tuberculosis 

 are considered to be potent sources of infection. 



It is possible, however, that infection through the agency 

 of milk occupies a more prominent position in the public mind 

 than the frequency of its incidence warrants. So much, in fact, 

 has been written on this subject in the daily papers, so many 

 laws and bye-laws are in force to render the lives of unfortunate 

 cow-keepers, dairymen and milk-vendors burdensome, that 

 were it not that individual experience teaches each and all of 

 us that the danger is vastly over-rated, no sane person to-day 

 would ever drink raw milk. 



Tuberculosis is no uncommon cause of death in young children. 

 As cows' milk is the staple food of the majority of infants during 

 the first year of life, a period when the relative death-rate is 



