Carpenter's principles of human physiology . that a simple tube (a) would delivermore fluid in a given time than a bifid one (&), the sectional areas of whose anus weretogether equal to a, and the bifid tube more than a trifid one (c) in the proportion of (a) 3860 :(b) 3400: (r) 3100, the pressure being equal in all three cases. t Thus Marey has shown that whilst elastic and rigid tubes of equal diameters will dis-charge an equal quantity of fluid as long as the stream is continuous, the moment the streambecomes intermittent an advantage is gained by the elastic tubes, apparently owing to thed
Carpenter's principles of human physiology . that a simple tube (a) would delivermore fluid in a given time than a bifid one (&), the sectional areas of whose anus weretogether equal to a, and the bifid tube more than a trifid one (c) in the proportion of (a) 3860 :(b) 3400: (r) 3100, the pressure being equal in all three cases. t Thus Marey has shown that whilst elastic and rigid tubes of equal diameters will dis-charge an equal quantity of fluid as long as the stream is continuous, the moment the streambecomes intermittent an advantage is gained by the elastic tubes, apparently owing to thediminution of friction in the latter, and the conversion of the jetting movement of the fluidinto a more continuous, uniform, and steady flow; and herein, perhaps, we may perceive anexplanation of the hypertrophy of the Heart, so frequently observed as a concomitant of arigid aorta in old age. See Annal. des Sci. Nat. Zool., 1857, t. viii. p. 330; and lnaugurale, 1859. 318 OF THE CIRCULATION OF THE BLOOD. Fig. 141. Il^&. that part, as indicated by the dotted line If, on the other hand, theoutlet be enlarged, the fluid will be discharged more easily, and the line of levelswill fall with great rapidity. Upon these principles M. Marey* has constructedan apparatus bearing some resemblance to the different systems of vessels inthe body, a constricted portion at o (Fig. 141) representing the capillaries,t and being preceded by awider portion for the Arte-ries, and followed by a stillwider one for the this instrument it mayshown physically thatpressure is highest inArterial vessels, whilst: much less in the Ca-pillaries, and is lowest inthe Veins. | It may also beshown that the mean ten-sion of an Artery diminishes in proportion to its distance from the heart,and is by so much the less in proportion as the capillaries are dilated,and thus constitute a smaller obstacle to the passage of the arterial facts, at least as regards the difference of th
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectphysiology, bookyear1
