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LVIII. As the arteries are always full during life, and as the blood 

 flows along them with less velocity, the greater their distance from the 

 heart, the blood which the contractions of the left ventricle send into the 

 aorta, meeting the column of blood already in that vessel, communicates 

 to it the impulse which it has received; but retarded in its direct progres- 

 sion, by the resistance of that column, it acts against the parietes of the 

 vessels, arid removes them to a greater distance from their axis. This 

 lateral action which dilates the arteries, depends, therefore, on the resist- 

 ance of the parietes of these cavities, always filled with blood, to that 

 which the heart sends into them. This dilatation, which is more consi- 

 derable in the large arteries than in the smaller ones, manifests itself by 

 a beat, known under the name of puke*. The experiments of Lamure 

 would lead one to believe, that another cause of this phenomena is a 

 slight displacement of the arteries, every time they dilate. These dis- 

 placements are most easily observed at their curvatures, and where* they 

 adhere to surrounding parts, by a loose and yielding cellular tissue. 



The pulse is more frequent in women, in children, in persons of small 

 stature, during the influence of the passions, and under violent bodily ex- 

 ercise, than in an adult man, of high stature, and of a calm, physical, and 

 moral nature. At an early period of life, the pulse beats as often as a 

 hundred and forty times in a minute. But as the child gets older, the 

 motion of the circulation slackens, and at two years old, the pulse beats 

 only a hundred times, in the same lapse of time. At the age of puberty, 

 the beats of the pulse are about eighty in a minute; in manhood, seventy- 

 five ; and lastly, in old men of sixty, the pulse is not above sixty. It is 

 slower in the inhabitants of cold, than in those of warm climates. 



Since the time of Galen, the pulse has furnished physicians with one 

 of their principal sources of diagnosis. The force, the regularity, the 

 equality of its pulsations, opposed to their weakness, inequality, irregu- 

 larity, and intermittence, afford the means of judging of the nature and 

 danger of a disease, of the power of nature in bringing about a cure, of 

 the organ that is most affected, of the time or period of the complaint, 

 Sec. No one has been more successful than Bordeu,in the consideration 

 of the pulse, under these different points of view. Its modifications in- 

 dicative of the periods of diseases, establish, according to that celebrated 

 physician, as may be seen in his Recherches sur le fiouls par rapfiort aux 

 crises, the pulse of crudity, of irritation, and of concoction. Certain ge- 

 neral characters indicate, whether the affection is situated above or be- 

 low the diaphragm, hence the distinction of superior and inferior fiulse. 

 Lastly, peculiar characters denote the lesion of peculiar organs; which 

 constitutes the nasal, guttural, pectoral, stomachic, hepatic, intestinal, 

 renal, uterine, Sec. 



Besides these sensible beats, which constitute the phenomenon of the 

 pulse in the arteries, there is an inward and obscure pulsatory motion, by 

 which all the parts of the body are agitated, every time that the ventri- 

 cles of the heart contract. There is a kind of antagonism between the 

 heart and the other organs, they yield to the impulse which it gives to 

 the blood, dilate on receiving this fluid, and collapse when the effort of 

 contraction is over. Every part vibrates, trembles, and palpitates within 



* See APPENDIX, Note S, for a different explanation of this phenomenon from that 

 given by Richerand. 



