MEDICINE IN MODERN TIMES. 725 



may turn out ultimately to be essential elements in problems, the 

 solution of which promotes directly and greatly the interests of 

 man, and the glory of Him to whom nothing is common or un- 

 clean. Could anything have seemed at first sight to be more 

 impertinent, more otiosely curious and trifling, than to enquire 

 during an epidemic of cholera what was the nature of the subsoil 

 in the area it was ravaging, to what depth it was porous, and at 

 what level the water was, and had been previously, standing in it ? 

 Yet, as I think. Von Pettenkofer has at last fought out and won 

 his battle on these points (see ^Zeitschrift fiir Biologic,' Bd. I, 

 Heft iii. und iv. 1865 ; Bd. II. Heft i. 1866 ; Supplemental Heft, 

 1867, p. 54; Bd. IV. Heft iv. p. 400); and the distinguished 

 President of our * Public Medicine ' section, Mr. Simon, who is as 

 little prone as most men of science to take up over-readily with 

 any new wind of doctrine, has told us (' Report of the Privy 

 Council for i856,' pp. 0^6 and 457) that certain of his carefully 

 observed cases of the distribution of this disease seem to illustrate 

 and find their explanation in Von Pettenkofer's theory. I have 

 pleasure in adding that I see, by papers published by the illustrious 

 Professor of Munich in the 'Allgemeine Zeitung^^ for June last, 

 that he has been able to show that, amongst all the other circum- 

 stances of the case at Gibraltar and at Malta, there were still to be 

 found, all guessing and objections notwithstanding, the porous 

 subsoil and the retreating ground-water, as factors in the complex 

 constituting an area or arena for cholera. Let us attend to and 

 note always all the circumstances in every complex phaenomenon 

 which we have to investigate, but let us not betake ourselves over- 

 hastily to the process of eliminating antecedents, until we are quite 

 sure that they do not enter as factors into its causation. 



I may say, in conclusion, that attention to this seventh rule of 

 Descartes might have saved such students of Natural Science as 

 have fallen into materialism from falling into it. The Physiologist, 

 as such, has nothing to do with the data of Psychology which do 

 not admit of being weighed or measured, nor of having their force 

 expressed in inches or ounces. This language, which I long ago 

 employed myself (^Nat. Hist. Rev./ April 1861; 'Med. T. and Gaz.' 



1 See also 'Allgemeine Zeitung,' December 8, 1868, No. 343. Ueber das Ver- 

 haltniss der "amtlichen Choleraberichte " zum Boden und Grundwasser.' Von Dr. 

 Max von Pettenkofer. 



