4 PEEFACE. 



can be accomplished much more efficiently, by dividing it 

 into separate and. distinct parts. By publishing each part 

 separately, the whole subject of human physiology, great as 

 it is, may be considered with a degree of elaborateness 

 which is generally looked for only in special treatises. 

 This does not necessarily involve great voluminousness ; 

 on the contrary, it frequently happens that subjects, the 

 literature of which is excessively abundant, may be con- 

 sidered, from a practical and positive point of view, in a 

 comparatively small space, ignoring nothing that is valu- 

 able, and taking pains only to compare and harmonize con- 

 flicting experiments and observations. A practical acquaint- 

 ance with experimental methods of observation frequently 

 enables the physiologist to accomplish this end, and thus re- 

 lieve certain complicated questions of much of their obscurity. 

 The subjects taken up in the present volume form a 

 subdivision of physiology of the greatest importance and 

 interest, to the general as well as to the professional 

 reader. The first of these, alimentation, does not always 

 receive sufficiently extended consideration in works upon 

 physiology; though it is evident that the properties and 

 physiological relations of matters which are destined to be- 

 come part of the living body can hardly be studied too 

 closely. The effects of improper and insufficient alimenta- 

 tion, also, which are too often observed in the poorer classes, 

 particularly in large cities, are of the highest importance. 

 The author, through the kindness of Dr. W. H. Yan Bu- 

 ren, of the United States Sanitary Commission, has been 

 enabled to present some important physiological facts con- 

 nected with the celebrated Anderson ville prison, noted on 

 the spot by Prof. Joseph Jones, M. D., formerly of Georgia, 



