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THE POPULAR SCIENCE MONTHLY. 



tiple simultaneous method, in which two or more vital movements — 

 for instance, of the heart, pulse, and respiration — are recorded at the 

 same time, showing their exact relations to each other. The sphygmo- 

 graph, in the compound form of Dr. Keyt (Fig. 5), with a chrono- 



Fig. 6. 



graphic attachment, is a modern mechanical help in stethoscopy of 

 great value, and has given important light on questions of physiology 

 and pathology. It is an instrument of precision, of scientific interest 

 and importance, and in difficult physical explorations the graphic 

 method is found almost indispensable. 



A few cases will now be given illustrative of practice in stetho- 

 scopy. A patient has the following symptoms : " Shortness of breath, 

 smotherings, cough with little expectoration, pain of the side, varying 

 from the sharp stitch to the dull and aching pain.*' The illness and 

 distress are evident, and though the question of present relief is upper- 

 most in the patient's mind, he has suflficient intelligence to demand 

 and to comprehend the cause. From the symptoms given it may 

 with about equally reasonable grounds be supposed that the trouble 

 depends upon organic changes of the heart, its valves, or its pericar- 

 dium ; of the lungs or their pleurae ; or upon disturbances not directly 

 connected with these organs at all, but arising from impressions trans- 

 mitted through the reflex system of nerves ; or it may be owing to a 

 combination of two or more of these causes. 



No amount of experience or tact will enable the physician to do 

 more than to guess the diagnosis from these symptoms. He is unable 

 to prescribe intelligently the needed means of relief and of the ex- 

 pected cure except by means of physical exploration of the chest. On 

 inspection, increased frequency of breathing is observed : this is a 

 8u"ggestion only. 



On applying the stethoscope the heart is found somewhat dis- 

 placed, but perfectly healthy as regards its size, its valves, its mem- 

 branous coverings — an important step by way of exclusion of certain 

 possible conditions. 



