344 Obituary Notices of Fellows deceased. 



In connection with the subject of contagion, reference should here 

 be made to the doctrine strongly enforced by the early sanitary 

 reformers who were Simon's immediate predecessors, that filth was the 

 enemy against which all measures for the prevention of zymotic 

 diseases must be chiefly directed. Recognizing that the belief in the 

 dependence of disease on dirt has a foundation in fact, he did his best 

 to bring its essential characters as a cause of disease into prominence, 

 so that its special meaning as a term to be commonly employed in 

 sanitary science should be well understood and determined. In the 

 introduction to a paper, published in 1874, on the subject, he shows 

 that sanitary improvement has always had for its foundation the broad 

 knowledge that filth makes disease. He then gives in detail the 

 reasons for concluding that filth, considered as a source of danger to 

 health, is never definable in chemical terms, and finally limits the 

 technical application of the word to those kinds of uncleanness which 

 contain, as their essential ingredients, morbific "ferments and contagia" 

 He leaves the question open whether the products of putrefaction are 

 necessarily morbific, but strongly objects to the assumption that the 

 presence or absence of offensive smell is to be considered as evidence of 

 infectiveness. In the battle that had to be fought in Simon's time for 

 cleanliness in public life, it was necessary to use plain words intelligible 

 to the ordinary reader.* In our pre-bacteriological ignorance, we had, 

 at that time, no direct knowledge of the enemies we had to contend 

 with, so that hand-to-hand fighting was out of the question. The 

 best that could be done was done. The best existing information was 

 brought to bear for the enforcement of cleanliness and of the rapid 

 removal of dangerous refuse, with results to the public health which 

 could scarcely have been surpassed had we been possessed of our 

 present knowledge. 



Of the scientific inquiries which were initiated by Simon in con- 

 nection with his official position, none were more fruitful than those 

 relating to the aetiology of pulmonary tuberculosis. Towards the end 

 of the sixties, the subject presented itself to his consideration from two 

 points of view from that of the local and occupational conditions 

 which had been recently ascertained to be operative in determining its 

 prevalence, and from that of experimental evidence of its infectivity. 

 A mass of new information as to the production of consumption by 

 dusty atmosphere and defective ventilation had been brought together 

 by means of local inquiries. On these followed the very remarkable 

 investigations of Dr. Buchanan, showing that, in the absence of any 

 personal conditions affecting the population, the drying of the soil 

 brought about by works of sewerage in towns had led to a marked 



* Loc. cit., pp. 451 et. seq. 



