458 HEALTH AND DISEASE 



about the head, rushing noises, tlirobbings, flushing of the face, giddiness, 

 sleepiness, irritability, impairment of the intellectual powers, or actual 

 mental derangement, disturbance of vision, movement of bodies before 

 the eyes, twitchings in the extremities, and attacks of faintness. 



It will be perceived that the majority of these symptoms would not be 

 recognized in the lower animals, and the few that would be apparent, such 

 as unsteadiness of movement, attacks of vertigo (megrims), or twitching in 

 the extremities, would possibly not be attributed to disease of the heart, 

 and would probably not be in any way connected with disturbance of that 

 organ. Under such conditions it is evident that a diagnosis must neces- 

 sarily be of an uncertain character, unless by some accident suspicion of 

 the true cause be aroused, and a careful examination of the heart lead 

 to the detection of certain morbid conditions. 



Physical Examination Of the Heart and its larger vessels can only 

 be undertaken by an expert who is familiar with the anatomy and physi- 

 ology of the organs of the circulatory system, and on this part of the 

 subject the reader is advised to consult the sections on the anatomy and 

 physiology of the heart. Armed with the knowledge thus obtained, even 

 the tyro will be able to realize the importance of constant experience in the 

 use of the instruments which are employed for the purpose of the exami- 

 nation of the heart and vessels, even if he does not contemplate devoting 

 himself sufficiently to the subject to obtain the necessary skill. In the 

 first place, the examination which will be required will have regard to 

 what can be ascertained by the use of the hand applied to the cardiac 

 region, and also to certain of the most superficial arteries. The amount of 

 force exercised by the heart in its contraction produces a distinct impres- 

 sion to the hand of the examiner when placed upon that part of the walls 

 of the chest against which it strikes or beats, and the impulse communi- 

 cated by the heart to the blood which passes through the arteries produces 

 a beat as nearly as possible at the same time as the contraction of the 

 heart. This is described as the pulse, and upon its character and frequency 

 some opinion may be formed as to the general condition of the central 

 circulatory organ, as previously described in the section relating to the 

 symptoms of disease. 



In the next place, percussion over the cardiac region, performed by a 

 light but sharp stroke with the points of the fingers, will make the 

 examiner acquainted with any alteration in sound as compared with that 

 emitted from the chest of the perfectly healthy subject. For example, where 

 dulness of sound is found to extend beyond the area of the healthy heart, 

 enlargement or hypertrophy of the organ would be suspected. 



Next to percussion, auscultation is employed by the use of the stetho- 



