Section I. 
SANITARY SCIENCE AND HYGIENE. 
1.— IS LEPROSY A TELLUEIC DISEASE ? 
By J. ASHBURTON THOMPSON, M.D . , D.P.H., Fellow of the British Institute 
of Public Health , Examiner in Hygiene at the University of Sydney , N.S.W. 
AEGUMENT. 
L ^? ere< ^ 1 ^ an inappreciable factor in lepriasis. Ma intenance of lepra independent 
of heredity. The contagion hypothesis. Hirsch’s critique thereof still holds. True 
significance of the discovery that lepra is a bacillary disease. Occasional direct 
communication of lepra by the sick cannot be formally denied, but direct communi- 
cation not the means of maintenance * Illustrations. General critique of evidence 
usually adduced to prove the contrary. 
II. Long-continued intimate contact with lepers often suffered with impunity : 
lepra often contracted when there has been no conscious contact with any leper. 
Inference, that lepra may be easily contracted under favourable circumstances, among 
which presence of an actual leper not essential. Reply to indirect objections to this 
argument : (a) Insignificance of a prolonged latent period when communicability is 
examined by epidemiological methods ; \b) hypothesis of indirect communicability 
not supported by ascertained facts. Importation of lepers does not give rise to new 
areas of endemicifcy. General critique of assertions to the contrary. Their crucial 
importance : if well-founded, the maintenance of lepra by communication with lepers 
would be established beyond dispute. Their want of foundation in ascertained fact. 
Illustrations. Negation. 
HI. Of comparative susceptibility. The physiology of defence. Poverty and 
filth incapable of reducing the efficiency of the defensive function as against lepra so 
as to account for maintenance. General critique of opinions to the contrary. 
Remarkable example of the island of Madeira. 
f ^ • Epidemiological facts show that lepra attaches to locality, or inheres in 
locality. Lepra comparatively rare among the population living on any endemic area 
nevertheless. Possible explanation. Value of the defensive function. Microbes 
favorisants. 
V. The liberty of lepers severely restricted by law in five colonies of Australia. 
I he origin and course of lepra on that continent entirely unknown. The five 
separate enactments consequently not based on any Australian evidence apparently 
showing that lepra is there maintained by communication with lepers. 
Upon the whole, I fail to see that anything has been added to our 
knowledge of the aetiology of lepra, or clipped away from our supposed 
knowledge, which requires alteration in the critical remarks made 
several years ago by Hirsch,* save in one respect. The exception 
regards heredity. Jt has always been known, and of course Hirsch 
noted it, that heredity is no necessary factor in lepriasis. We see that 
leprosy in whites almost always occurs in Australia under circum- 
stances which absolutely exclude it. I am aware of but one exception 
put of many instances. Secondly, it appears that, if heredity have any 
influence at all in this connection, at all events it is not the disease 
itself which is transmitted. IS o child ever has been born leprous, nor 
has any ever become leprous so young that it might reasonably be 
suspected of having suffered from birth. f But whether heredity were 
* “ Geographical and Historical Pathology.” 
f But see “Voyages cher les lepreux par M. 
1891, p. 340 ; also the observation 5, p. 370. 
le docteur Zambaco Pacha,” Paris, 
