382 RESPIRATION, 



the rudest empiricism could venture to adopt as explanations for 

 the recognition, diagnosis, and prognosis of diseases, whilst at the 

 present time, although our knowledge of the interchange of gases, 

 and the influence of the movements of the respirati ,n and the 

 circulation may not always afford definite conclusions, it can, at 

 least, supply us- with certain indications of the most essential 

 constituents of the pathological process, by which we may regulate 

 and modify our medical treatment. The more exact knowledge of 

 the respiratory functions which we now possess has thrown a 

 clearer light on the process of fever than any of the innumerable 

 treatises which have been written on the subject. We are 

 indebted to pure physiological investigations for numerous 

 elucidations of some of those groups of symptoms which we meet 

 with in certain diseases, such as pulmonary tuberculosis, emphy- 

 sema, certain heart-diseases, diabetes, &c. No one can deny that 

 the great advance which has been made in modern times in respect 

 to our knowledge of respiration, has afforded us a deeper insight 

 into these and many other pathological processes, but it would 

 carry us too far were we to enter more fully into the results 

 yielded in this respect by pure physiology to pathology. It is in 

 his practice by the bedside that the physician obtains the most 

 important aid from the physiology of the respiration. We do not 

 exaggerate when we assert that there is scarcely a page of this 

 section on the respiration which does not treat of facts from which 

 the physician may obtain the most valuable hints for his treatment 

 of various diseases, and more especially of pulmonary affections. 



While the advances of the science of medicine have taught us 

 that of all the vast accumulation of remedies which in the course 

 of time have been collected together, very few are of any value at 

 the bedside, and while the enlightened practitioner is disposed to 

 attach at least as much importance to a rational dietetic as to a 

 specifically therapeutic mode of treatment, the value of in- 

 vestigations on normal respiration, in reference to the science of 

 medicine, can never be over-rated ; for when once the fact is 

 universally admitted that the first thing to be considered in many 

 diseases is to furnish a copious supply of oxygen to the blood 

 which has been loaded with imperfectly decomposed substances, 

 and to remove as speedily as possible the carbonic acid which has 

 accumulated in it, these observations will have afforded us true 

 remedial agents, which exceed almost every other in the certainty 

 of their action. We may perhaps aid a tuberculous patient quite 

 as much by recommending him to respire a moist warm air, as if 



