292 ELECTRO-PHYSIOLOGY. 



I shall begin by briefly citing some instances of phenomena which have been 

 referred to the domain of animal electricity, but Avhich do not in reality pertain 

 to it. Thus it was customary, as may be learned from books not of recent date, 

 to cite as a proof of animal electricity the phenomenon developed by stroking 

 with the hand a living cat, or in taking off silk stockings in dry weather. These 

 are effects of electricity developed by rubbing, and may be equally obtained by 

 rubbing with the hand a muff made of a cat's fur. Those also were called cur- 

 rents of animal electricity which resulted from touching with the two ends of the 

 galvanometer the tongue and the forehead when wet with perspiration, or from 

 introducing these ends into the liver and stomach of a living animal. Currents 

 indeed arise, but they are of the same nature with those which we obtain by 

 dipping the extremities, one in a solution of potassa, the other in sulphuric or 

 nitric acid, thus bringing the two liquids into communication. In this experi- 

 ment a piece of cloth is immersed in the acid, another piece in the alkali, the 

 two pieces are placed in contact, the circuit closed by the extremities of the gal- 

 vanometer, and we have a direct current from the alkaline to the acid cloth. Now 

 the sweat is an acid, as is also the gastric juice of the stomach, the saliva and 

 bile have an alkaline reaction, and hence there are direct currents in the animal 

 from the alkaline to the acid liquids. Belliugeri, a distinguished Turiuese physi- 

 ologist, in a memoir on the electricity of animal liquids, thought that he had 

 discovered electro-physiological phenomena, properly so called. He used to 

 operate with a voltaic pair of plates, sometimes on the arterial blood, sometimes 

 on the venous, and again on the urine or saliva. These phenomena, rightly con- 

 sidered, are, and indeed cannot be other than, electro-chemical, and the differ- 

 ences, whatever they may be, depend on the chemical composition of those 

 liquids and their different conductibility. It has been also said that the electric 

 current being passed into albumen, or white of egg, produced organization. The 

 flict is that albumen is coagulated around the electrodes, because these and the 

 liquid grow warm from the passage of the current, and because the acid and 

 alkali produced by the electrization cause the albumen to coagulate. 



I have multi])lied these examples, because no doubt should be permitted to 

 remain, especially in the beginning of this course, respecting the distinction 

 which it is requisite to make between electro-physiological phenomena really 

 pertaining to the living organism, and the electrical effects which are produced 

 in animal or vegetable tissues whether alive or dead, and which are due to known 

 physical or chemical actions. Of this kind are certain other effects of electricity 

 on vegetation in which there has been a more persistent disposition to see a re- 

 lation between electricity and the living organism. 



You are, perhaps, not ignorant that there is an aquatic plant, the cliara, 

 whose stalk, observed with the microscope, presents a singular phenomenon. 

 It is divided into compartments, in each of which are seen regularly moving or 

 circulating globules or cellules. These movements, the cause of which is un- 

 known, stop when an electric discharge passes through the stalk, and all circu- 

 lation finally ceases if the discharge is very strong. We must infer that the 

 discharge acts either by mechanically destroying the structure of the plant, or 

 coagulating the liquid which it contains, or by altering the chemical composi- 

 tion, effects which all suffice to explain the observed results. 



An eminent physicist of Turin, Vassalli-Eandi, made a series of ingenious 

 experiments to show that seeds exposed frequently in the focus of an ele *tric 

 'machine germinate before others not thus electrified. I know not whether there 

 has been any verification of this fact, but it might be accounted for by attrib- 

 uting the effect to the oxygen, or rather to the ozone, which is known to favor 

 germination ; and ozone is formed in contact with the electrical focus. I have 

 here the usual ozonemetric paper covered with iodine of potassa and baked 

 starch, and it will be seen that, under the electric discharge, the paper becomes 

 blue, an effect which is due to the ozon«. 



