320 APPENDIX. 



But the chemical constitution of the fluid, and its physical 

 and chemical relation to the animal membrane which it 

 permeates, seem to have an important influence on the 

 phenomenon. The phenomenon of the endosmosis of 

 gases, on which M. Faust (Amer. Med. Jour. Vol. VII. 

 Froriep's Not. N. 646,) has instituted experiments, are 

 very remarkable. A bladder half filled with atmospheric 

 air being placed under a jar containing carbonic acid, 

 becomes more distended ; and if the bladder which is 

 placed in the carbonic acid gas contained hydrogen, it 

 becomes distended to bursting. If, on the contrary, the 

 jar contains the lighter, and the bladder the denser gas, 

 the bladder becomes collapsed. (Muller's Elements of 

 Physiology, p. 245.) Gases also permeate moist animal 

 textures, and will be absorbed by fluids within them. 

 This explains how gaseous matters can enter into the 

 blood without the globules of the blood escaping. 



ACTION OF THE HEART. SEE PAGE 56. 



The contraction (systole) only of the heart is an active 

 state ; the dilatation (diastole) is the moment of repose, in 

 which the fibres are relaxed, and ,in which the blood is 

 poured from the contiguous veins into the cavities of the 

 heart, to Jill the vacuum consequent on the relaxation of its 

 fibres ; the valves of the heart being so arranged as to 

 allow the influx of the blood from the veins. (Muller's 

 Physiology, Vol. I. p. 173.) See also the experiments of 



