xlii 



that he " had always shown himself of extraordinarily active and 

 discriminating mind, and always intent on that exactitude which is 

 essential to scientific accuracy." 



For some seven years Buchanan acted professedly as a temporary 

 and occasional Inspector in the Medical Department of the Privy 

 Council, but his services were such that he soon came to be continu- 

 ously engaged in the work of the Department, and in 1868 he 

 received permanent appointment. In 1871 he was, with his chief and 

 others, transferred to the newly formed Local Government Board. 



During his seven years of temporary duty Buchanan undertook a 

 number of important enquiries. One, which stands out very promi- 

 nently, was a comprehensive investigation into the effects on health 

 which had resulted from the large works of drainage and water 

 supply carried out in a number of our towns and cities. As this 

 enquiry progressed, Buchanan came to see that the influence which 

 had been exerted by these works was by no means limited to a 

 reduction in the rate of mortality from those diseases which are com- 

 monly associated with the pollution of air, soil, and water, and he 

 soon arrived at the conclusion that the drying of the soil brought 

 about by works of deep drainage had been associated with a marked 

 reduction in the mortality from phthisis. This point was worked out 

 m much detail, and Buchanan was able to show that the diminution 

 m the phthisis death-rate bore a distinct relation to the extent to 

 which the level of subsoil water was lowered as the result of works 

 of drainage ; that the phthisis death-rate oscillated in one and the 

 same town with variations — of sufficient duration — in the oscillations 

 of the subsoil water; and that where, owing to physical or other 

 circumstances, no lowering of the subsoil water had resulted from 

 works of drainage, there had been no material diminution in the 

 amount of death from phthisis. 



This discovery has had an important influence on public health 

 administration, and it has formed the basis of codes of bye-laws having 

 for their object the exclusion of moisture and sub-soil emanations into 

 the interior of dwelling-houses. It also became the more interesting 

 when it was ascertained, after the publication of Buchanan's reports, 

 that Dr. Bowditch, of Massachusetts, had been making enquiries on 

 somewhat the same lines, and had independently arrived at very 

 similar conclusions. 



As has already been said, through his studies at the London Fever 

 Hospital, Buchanan came to possess a highly scientific knowledge of 

 the various continued fevers ; and he was the writer of the article on 

 typhus fever in Reynolds' ' System of Medicine,' in addition to a 

 number of official reports having to do with the etiology of the specific 

 fevers. Perhaps one of the most important of ther-e was one relating 

 to an outbreak o* enteric fever at Cuius College, Cambridge, in which 



