76 



ANIMAL CHEMISTRY. 



In cases of a different kind, where artifi- 

 cial external disturbance produces no effect, 

 the physician adopts other indirect methods 

 to exalt the resistance offered by the vital 

 force. These methods, the result of ages 

 of experience, are such, that the most per- 

 fect theory could hardly have pointed them 

 out more acutely or more justly than has 

 been done by the observation of sagacious 

 practitioners. He diminishes, by blood- 

 letting, the number of the carriers of oxy- 

 gen, (the globules,) and by this means the 

 conditions of change of matter ; he excludes 

 from the food all such matters as are capa- 

 ble of conversion into blood ; he gives 

 chiefly or entirely non-azotized food, which 

 supports the respiratory process, as well 

 as fruit and vegetables, which contain the 

 alkalies necessary for the secretions. 



If he succeed, by these means, in dimi- 

 nishing the action of the oxygen in the blood 

 on the diseased part, so far that the vital 

 force of the latter, its resistance, in the 

 smallest degree overcomes the chemical ac- 

 tion ; and if he accomplish this, without ar- 

 resting the functions of the other organs, 

 then restoration to health is certain. 



To the method of cure adopted in such 

 cases, if employed with sagacity and acute 

 observation, there is added, as we may call 

 it, an ally on the side of the diseased organ, 

 and this is the vital force of the healthy 

 parts. For, when blood is abstracted, the 

 external causes of change are diminished 

 also in them, and their vital force, formerly 

 neutralized by these causes, now obtains the 

 preponderance. The change of matter, in- 

 desd, is diminished throughout the body, 

 and with it the phenomena of motion : but 

 the sum of all resisting powers, taken to- 

 gether, increases in proportion as the 

 amount of the oxygen acting on them in the 

 blood is diminished. In the sensation of 

 hunger, this resistance, in a certain sense, 

 makes itself known ; and the preponderating 

 vital force exhibits itself, in many patients, 

 when hunger is felt, in the form of an ab- 

 normal growth, or in abnormal metamor- 

 phosis of certain parts of organs, Sympar- 

 thy is the transference of diminished resist- 

 ance from one part, not exactly to the next, 

 but to more distant organs, when the func- 

 tions of both mutually influence each other. 

 When the action of the diseased organ is 

 connected with that of another when, for 

 example, the one no longer produces the 

 matters necessary to the performance of the 

 functions of the other then the diseased 

 condition is transferred, but only apparently, 

 to the latter. 



In regard to the nature and essence of the 

 vital force, we can hardly deceive ourselves, 

 when we reflect, that it behaves, in all its 

 manifestations, exactly like other natural 

 forces ; that it is devoid of consciousness or 

 of volition, and is subject to the action of a 

 blister. 



The nerves, which accomplish the volun- 

 tary and involuntary motions in the body, ! 



' are, according to the preceding exposition, 

 not the producers, but only the conductors 

 of the vital force ; they propagate motion, 

 and behave towards other causes of motion, 

 which in their manifestations are analogous 

 to the vital force, towards a current of elec- 

 tricity, for example, in a precisely analo- 

 gous manner. They permit the current to 

 traverse them, and present, as conductors 

 of electricity, ail the phenomena which they 

 exhibit as conductors of the vital force. In 

 the present state of our knowledge, no one, 

 probably, will imagine that electricity is to 

 be considered as the cause of the phenomena 

 of motion in the body ; but still, the medi- 

 cinal action of electricity, as well as that of 

 a magnet, which, when placed in contact 

 with the body, produces a current of elec- 

 tricity, cannot be denied. For to the ex- 

 isting force of motion or of disturbance there 

 is added, in the electrical current, a new 

 cause of motion and of change in form and 

 structure, which cannot be considered as al- 

 together inefficient. 



Practical medicine, in many diseases, 

 makes use of cold in a highly rational man- 

 ner, as a means of exalting and accelerating, 

 in an unwonted degree, the change of matter. 

 This occurs especially in certain morbid con- 

 ditions in the substance of the centre of the 

 apparatus of motion 5 when a glowing heat 

 and a rapid current of blood towards the 

 head point out an abnormal metamorphosis 

 of the brain. When this condition continues 

 beyond a certain time, experience teaches 

 that all motions in the body cease. If the 

 change of matter be chiefly confined to the 

 brain, then the change of matter, the gene- 

 ration of force, diminishes in all other parts. 

 By surrounding the head with ice, the tem- 

 perature is lowered, but the cause of the 

 liberation of heat continues ; the metamor- 

 phdsis, which decides the issue of the dis- 

 ease, is limited to a short period. We must 

 not forget, that the ice melts and absorbs 

 heat from the diseased part ; that if the ice 

 be removed before the completion of the 

 metamorphosis, the temperature again rises ; 

 that far more heat is removed by means of 

 ice than if we were to surround the head 

 with a bad conductor of heat. There has 

 obviously been liberated in an equal time * 

 far larger amount of heat than in the state 

 of health ; and this is only rendered possible 

 by an increased supply of oxygen, which 

 must have determined a more rapid change 

 of matter. 



The self-regulating steam engines, in 

 which, to produce a uniform motion, the 

 human intellect has shown the most ad- 

 mirable acuteness and sagacity, furnish no 

 unapt image of what occurs in the animal 

 body. 



Every one knows, that in the tube which 

 conveys the steam to the cylinder where the 

 piston-rod is to be raised, a stop-cock oi 

 peculiar construction is placed, through 

 which all the steam must pass. By an ar- 

 rangement connected with the regulating 



