42 PHYSIOLOGICAL RELATIONS OF CELLULAR TISSUE. 



CHAPTER VI. 



ON THE GREAT MECHANICAL FORCES GENERATED BY THE CAPILLARY ATTRACTION OF 



CELLULAR TISSUE. 



(From the American Journal of the Medical Sciences for May, 1838.) 



CONTENTS : Physiological Relations of Cellular Tissue. Force with which Gases and 

 Liquids pass through Cellular Tissue. Disturbing Action of Leakage. The Capil- 

 lary Force overcomes powerful Mercurial Pressure. Dalton's Hypothesis. The Tis- 

 sue is the Origin of the Force. Its Absorbent and Condensing Action. Voltaic 

 Batteries may be used for producing great Pressures. Gases pass when resisted by 

 the Force of many Atmospheres. The condensed Gas acts as a Vacuum. Co-ordina- 

 tion of the Results of Dalton, Graham, and Mitchell. Disturbing Agencies. Dis- 

 turbance by Variation of Temperature. Physiological Experiments and Remarks. 



135. OF all bodies, those alone are capable of exhibiting the phenomena of life which 

 consist of a cellular structure. Identity of chemical constitution does not appear to be 

 essential, yet it is only a limited number out of the long list of chemical elements that are 

 capable of organization ; these, if left alone to satisfy the conditions of their affinities 

 undisturbed, would most commonly give rise to the production of water, ammonia, and 

 carbonic acid. Life, therefore, in this point of view, has no other action than to disturb the 

 play of these affinities, and force the elementary atoms into. other forms of combination ; 

 it depends upon the success of this action whether a living or inorganic mass shall 

 result. A living body is endued with a peculiarity of form, and does not require an 

 identity of composition ; an inorganic body depends for its nature on certain and definite 

 composition, without any relation to structure. It. is true that most bodies, whether ele- 

 mentary or composite, exhibit a marked tendency to geometrical arrangements, and 

 all crystallizations are brought about by the operation of polar forces, but an inorganic 

 compound body does not of necessity require any peculiar crystalline shape, or other 

 form, for existence. 



136. Life, then, is a state of force ; the system of nature presents us with but four 

 of the chemical elements subject to it, for we are taught to make a distinction between 

 crystalline arrangement and living structure. We have not any direct evidence to show 

 that all simple substances are in any wise obedient to the laws of vitality, or that, when 

 they assume symmetrical arrangements round an axis, that it is an approach to organiza- 

 tion, an imperfect organization depending on the sluggishness of their character or the 

 incompetency of the vital forces to control the range of their affinities ; nor is there any 

 proof that the laws directing the atomic arrangement of macled crystals bear any sort 

 of analogy with those that direct the structural deposite of the radiated class of animals. 

 It is true that the passage of a polarized ray of light through transparent crystals has 

 disclosed to us the fact that their atomic constituents are held together in a state of 



