Page:The Principles and Practice of Medicine.djvu/23



commencing the study of General Pathology, our attention must be devoted to the following points: ]st, the nature and constitution of disease (Pathogeny or Pathology proper) ; 2nd, its causes (Etiology); 3rd, its prevention (Hygienics); 4th, its cure (Therapeutics).

Before, however, entering upon the study of disease, it will be useful to take a general view of the manner in which it is capable of causing death. This is not an inquiry of merely physiological interest ; it has very important practical bearings, as will be hereafter fully elucidated.

When a person in robust health, suddenly struck down by an attack of apoplexy, becomes unconscious and dies in a few hours, it is clear that there is something in the manner of dying diffe- rent from that of a person who, long suffering from consump- tion, retains his senses to the last and sinks so gradually, that the moment of death can scarcely be determined. There must be, it is evident, a difference, to say the least, as to the order in which the various vital functions cease, but we shall also find that there is a difference in the commencement or starting point of their cessation.

. Death may be due to the blood not circulating through the vessels, or not being oxygenated in the lungs ; or in other words, to failure of the heart's action, SYNCOPE or of the respiratory function, APNCEA. In disease, death does not usually arise from the direct cessation of one or other of these great functions, but in most instances from the gradual impairment and failure of both, and of other important functions in relation with them. When however sudden, or caused by