660 THE POPULAR SCIENCE MONTHLY. 



Another important discovery of the last century was the determi- 

 nation of the cause of the well-known lead-colic by Sir George Baker. 

 This opened up the large Held of metallic poisoning which has received 

 so much elucidation and proved of such importance in reference to the 

 water-supply of large communities. 



In the present century we have to point to the establishment of 

 the fact of the water-carriage of disease, with which the name of Snow 

 is so honorably associated, the differentiation of continued fevers by 

 Stewart and Jenner, and their connection with the poison of infected 

 excreta by the labors of Budd and other eminent men. To those we 

 must add the elaborate investigations into the modes of propagation 

 of cholera, dysentery, and other tropical diseases, and the means by 

 which scarlet fever, diphtheria, etc., are carried from place to place by 

 various channels of communication. It would be unadvisable, even if 

 it were possible, to enter into details on these points, but there is one 

 branch of the subject on which we must dwell for a little. No in- 

 quiry can assume a scientific form unless it has a numerical basis to 

 work upon, and therefore it behooves us to note the starting-point of 

 such a basis in hygiene, if we can find it. This we do find in the col- 

 lection of statistics, a beginning of which was made a long time ago 

 in the bills of mortality kept in this country. We know how imper- 

 fect those were, and how even the population of this country was not 

 correctly known until within the lifetime of men still living. But 

 still beginnings were made, and the question taken up more and more 

 enthusiastically by enlightened men, until at last the Government 

 Statistical Department was formed, and that remarkable series of re- 

 ports begun which will immortalize the name of William Farr. From 

 that time the future of hygiene was assured ; for there was sound 

 ground to work on, and, if we add to that the valuable reports on the 

 health of towns published by the commission of which the present 

 Duke of Buccleuch was president, we shall have stated some of the 

 most important foundations of modern sanitary science. Those re- 

 ports disclosed a state of things little dreamed of, and the statistical 

 returns compiled by Dr. Farr showed how much the life and health 

 of the nation were dependent upon the conditions in which its individ- 

 ual members were placed. The establishment of the General Board 

 of Health, under Mr. Chadwick, was one of the valuable outcomes of 

 this remarkable movement. Although the original Board of Health 

 was brought to an end in 1854, yet its work has been continued and 

 expanded under Mr. Simon, his colleagues and successors, in spite of 

 many difficulties and obstacles. 



The part which the public services, such as the army and navy, 

 played in the progress of hygiene was very important, as might in- 

 deed be expected ; for under no other circumstances could bodies of 

 men be so well observed, and the effects of surroundings and condi- 

 tions upon health noted. Accordingly, we have a long roll of names 



