A treatise on human physiology / By John C. Dalton, jr.

  • Dalton, John Call, 1825-1889.
Date:
1859
Catalogue details

Licence: Public Domain Mark

Credit: A treatise on human physiology / By John C. Dalton, jr. Source: Wellcome Collection.

Provider: This material has been provided by the Augustus C. Long Health Sciences Library at Columbia University and Columbia University Libraries/Information Services, through the Medical Heritage Library. The original may be consulted at the the Augustus C. Long Health Sciences Library at Columbia University and Columbia University.

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    interior of the body, whicli result in the formation of new sub- stances ; all these active phenomena belonging necessarily to the domain of Physiology. The description of the proximate principles of animals and vege- tables will therefore be introduced into the following pages. The description of the minute structures of the bodj', or Micro- scopic Anatomy, is also so closely connected with some parts of Phy- siology as to make it convenient to speak of them together; and this will accordingly be done, whenever the nature of the subject may make it desirable. III. The study of Physiology, like that of all the other natural sciences, is a study of phenomena, and of phenomena alone. The essential nature of the vital processes, and their ultimate causes, are questions which are beyond the reach of the physiologist, and cannot be determined by the means of investigation which are at his disposal. Consequently, all efforts to solve them Avill only serve to mislead the investigator, and to distract his attention from the real subject of examination. Much time has been lost, for example, in discuss- ing the probable reason why menstruation returns, in the human female, at the end of every four weeks. But the observation of nature, which is our only means of scientific investigation, cannot throw any light on this point, but only shows us the fact that men- struation does really recur at the above periods, together with the phenomena which accompany it, and the conditions under which it is hastened or retarded, and increased or diminished, in intensity, duration, &c. If we employ ourselves, consequently, in the discus- sion of the reason above mentioned, we shall only become involved in a network of hypothetical surmises, which can never lead to any definite result. Our time, therefore, will be much more profitabl}^ devoted to the study of the above phenomena, which can be learned from nature, and which constitute, afterward, a permanent acquisi- tion. The physiologist, accordingly, confines himself strictly to the study of the vital phenomena themselves, their characters, their frequency, their regularity or irregularity, and the conditions under which they originate. When he has discovered that a certain phenomenon always takes place in the presence of certain conditions, he has established what is called a general principle, or a Law of Physiology.