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only in such extreme cases, but in others in which it is not so high, whether it proceeds 

 from without or within. Often the excessive production of heat has no salutary 

 tendency, when it is necessarily still more important to moderate it. The most powerful 

 means furnished by external agents consists in the application of water of a suitable 

 temperature. It is evident that this reduces the temperature of the body. He explains 

 the advantages which have frequently been derived from the use of cold water under the 

 varied forms of baths, douches, and affusions, in cases of the extraordinary development 

 of heat.' Dr. Hodgkin comments on this, and goes on to say, ' In conjunction with the 

 researches of Dr. Currie, of Liverpool, they will afford the most valuable assistance in the 

 regulation of clothing, of exposure to open air, of confinement within doors, and of the 

 application of the various forms of baths.' " (S.Wilks, Guy's Hospital Reports, 1878.) 



Returning to the subject of the respiratory processes in the 

 lungs and in the tissues, further progress was not possible until there 

 were new methods. This came when it was possible to extract the 

 gases of the blood and tissues, and to measure their respective 

 amounts and relations in arterial and venous blood and other fluids. 

 Mayow knew that blood gave off gases to a vacuum (1670). 

 Humphry Davy, in 1799, obtained the blood gases by heating the 

 blood, but before this Priestley had obtained carbonic acid from blood 

 by passing through it another gas, a method used much later by 

 Bernard (1857), only he used carbonic oxide. With the invention of 

 the mercurial gas pump, and the extraction of the blood gases by 

 means of it, a new chapter in modern physiology began. Gustav 

 Magnus in 1837 (Poggendorff's Ann. 40, p. 594) was thus able to 

 analyse the gases of arterial blood. At once, the names of Ludwig, 

 Pfliiger, and their pupils, Bunsen, Lothar Meyer, Regnault and Reiset, 

 P. Bert, L. Hermann, and many more occur to one. With this 

 subject are closely linked the discoveries in the chemistry of the blood 

 its haemoglobin and the remarkable properties of this pigment, with 

 which the names of Sir George Gabriel Stokes (Proc. Roy. Soc., 1846), 

 Hoppe-Seyler (1825-1895), W. Preyer (1841-1897), and many others, 

 are associated. All of which is part of modern physiology, and here 

 I leave the subject. 



One would like also to write the story of the coagulation of the 

 blood connected with the names of Wm. Hewson, Denis, Andrew 

 Buchanan, Alex. Schmidt, &c. but at the moment this is impossible. 

 We must, however, refer to some problems in connection with the 

 circulation of the blood, in the solution of which our own country- 

 men have led the way and furnished methods not only for physiology, 

 but also for all cognate sciences. 



