SECTIONV.General reflections on the action and influence which Galvanism, considered in a medical point of view, exercises on the animal œconomy.I shall not here speak of the variation in insensible perspiration, and of the increase of circulation, which, according to the observations of several physicians, are found to be produced by Galvanism. Similar phænomena, as is well known, take place during the administration of common electricity. I shall therefore confine myself to those effects which hitherto have been produced only by the action of Galvanism. I shall observe in the first place, that Galvanism, as already shown in the Experiments detailed in the Second Part, is capable of effecting a separation of the fluids, and even sometimes of protruding the fæcal matters from the body. In the case of the decapitated malefactor, I found that when the arc was applied to one ear and to the lips, a very sensible portion of saliva was discharged from the mouth. This observation was confirmed at Genoa on the head of an ox, and in several other places on the heads of sheep. The phænomenon of the extrusion of the fæcal matters from the trunk of an ox, by means of Galvanism, wasobserved also by Professor Mojon of Genoa, and his brother, to take place in human bodies. Considering the animal fluids separately, I have found that very great variations are produced in them by Galvanism. But before I give an account of the experiments which I made on this subject, I shall describe the apparatus I employed.The animal fluid destined to be exposed to the action of Galvanism is put into a glass vessel (PlateIII.fig. 6.) covered by a wooden lid, having in it two holes equally distant from the centre. Two wires, one of brass and the other of plated copper, the upper extremities of which are bent into the form of a hook, pass through these holes in such a manner, that the lower extremities of them reach nearly to the bottom of the vessel, where they are bent at right angles, so that only a very small interval is left between them. The upper extremity of one is made to communicate with the bottom of the pile, and the other with the summit. In consequence of this arrangement the Galvanic fluid is obliged to traverse the animal fluid, by which means it exercises an action on it according to the distance of the wires, and by its action separates from its different strata sometimes one principle and sometimes another; and this secretion will be effected with more ease and in greater abundance, according as the action of the pile is stronger, and the capacity of the conductors more considerable.EXPERIMENTI.Having put into glass vessels four ounces of blood recently drawn from the vein of a person in good health, I left one of them exposed to the contact of the atmospheric air, and subjected the other to the action of the pile. In both these portions I observed a speedy coagulation of the crassamentum, and at the end of twenty-four hours the serous part was separated. The blood exposed to the action of the pile adhered so strongly to the two wires immersed in it, that it was difficult to separate them from the clot which was thus suspended in the aqueous fluid, but in the other vessel the clot remained at the bottom.EXPERIMENTII.I put two equal portions of bile, still warm, taken from the gall-bladder of an ox, into two glass vessels, exposed one of them to the contact of the air, and subjected the other to the action of the pile. After ten hours had elapsed, I observed that the bile in the latter had become so opake as no longer to afford a passage to the light; while the other portion, exposed to the atmosphere, retained its transparency and colour. I observed also a considerable disengagement of air, the nature of which I have not yet had an opportunity of examining.EXPERIMENTIII.I took four ounces of urine, voided by a man in good health, exposed it to the action of the pile, and at the end of twenty-four hours found that the greater part of its constituent principles was separated. A portion of them was collected around the wires in such a manner as to form cylindric bodies of a considerable diameter, of which the wires were the axes. As the mass of the attracted matters increased, a portion fell to the bottom by its own weight. The cylinders were soon entirely destroyed, and the substances which formed them were precipitated by the least shock given to the vessel. I repeated this experiment lately in Mr. Wilson’s anatomical theatre in Windmill-street; and I observed, at the end of eighteen hours, a great quantity of the moleculæ furnished by the urine adhering to the two wires. But at length, not being able to withstand the effect of its gravitation, it began to fall down, forming a sort of wedge, the apex of which was at the surface of the urine, and the base at the bottom of the vessel.EXPERIMENTIV.Instead of putting the urine into a common apparatus, if a glass syphon with two platina wires be employed (Plate III. fig. 5.), the urine becomes limpid on the one side, and turbid on the other. The substance detached from the urineafterwards appears in the form of flakes, which are attracted by the platina wires. I observed this phænomenon for the first time in the company of those celebrated chemists Fourcroy and Vauquelin, while they were performing Galvanic experiments in their own laboratory.EXPERIMENTV.The substance above mentioned, which was precipitated to the bottom, when separated by filtration and dried, weighed about the fourth of a grain, and the fluid separated from it was of a greenish colour. On examining the earthy deposit of this urine, we obtained sulphate of lime by adding to it sulphuric acid.EXPERIMENTVI.Having exposed to the action of the pile, in the same manner, four ounces of urine voided by a person with jaundice, I obtained an earthy sediment, the weight of which was nearly equal to that above mentioned. The liquor separated from it was transparent, inclining a little to black. By the same chemical process I obtained sulphate of lime, though the sediment of the urine was somewhat dark, and afforded a portion of carbon and bile which inflamed in the fire.EXPERIMENTVII.Having repeated the above experiments with different kinds of urine, I observed in general, that Galvanism, by a peculiar attraction, separates from urine the sulphates and muriates united to a portion of the bile, and also to carbon, which in a great part are precipitated to the bottom of the vessel: the other part, which remains attached to the wires, exhibits a regular saline crystallization, of so singular a form that it seems worthy of becoming an object of further research to chemists.The examination of urine voided by persons labouring under different kinds of disease, seems to be an object sufficient to excite the curiosity of physicians. To expose to the action of Galvanism artificial aëriform fluids, analogous to those which act a part in the animal œconomy, might also be attended with advantage. For this purpose it will be convenient to employ the apparatus represented inPlateIII.fig. 7, which was lately constructed, with great precision, by M. Dumoutier at Paris. The whole artifice consists in a vertical metal tube, which can be raised up or pushed down. It is furnished with a stop-cock, and the tub in which the apparatus is placed has another. If the inverted bell be filled with water, and connected, by means of the vertical tube, with the apparatus which is to supply the gas, on opening the lower cock, the water will descend in the bell,and its place be supplied by the gas intended to be subjected to experiment.From all the observations hitherto made, there seems to be reason to conclude, that the effects produced on the animal œconomy by common electricity and by the Galvanic pile are different. The phænomena of artificial Galvanism give us some right to suppose, that a similar action is exercised by the Galvanic fluid circulating in the fluids and in the organs of living animals. In this point of view Galvanic researches may one day throw great light on the nature of secretion; and it may perhaps be found necessary, when remedies are administered, to take its influence into consideration: for it is possible that the action of these remedies in the animal œconomy may depend on the establishment of such an arc between the system of the nerves and that of the muscles, as may not alter the natural state of the Galvanic fluid proper for the constitution of the individual to whom these remedies are administered. All this however is mere conjecture, and must be classed with many other things in the theory of Galvanism which are still involved in obscurity, and which we can hope to see explained only by new researches and new experiments.Taking a general view of this Third Part, I must observe that the administration of Galvanism, when the above experiments are carefully examined, seems to appear in a muchmore advantageous point of view than before. I have indeed proved:1st. That Galvanism, on many occasions, exercises an influence different from that of common electricity, and that it may be administered in various cases with great ease and safety.2d.That the action of Galvanism manifests itself by a sensible attraction between the nervous and muscular parts; which seems to confirm the hypothesis of Humboldt, who supposes a Galvanic atmosphere peculiar to these parts when in a state of perfect vitality.3d.That the strong impression made by Galvanism on the brain seems to explain its power on the organ of hearing; and therefore the physicians of Berlin, and other parts of Germany, are entitled to great praise for their researches on this subject.4th. That though medicine is capable of affording considerable aid in cases of drowning and of asphyxia, it presents us with no means so powerful as Galvanism. The experiments made at London, Jan. 17, 1803, on the body of Forster, executed for murder, have fully convinced me of the activity of this stimulant.5th. That in cases of melancholy madness, when otherremedies fail, Galvanism may be employed with the greatest hopes of success, provided the disease does not proceed from a vitiated constitution, or a general derangement in the animal machine.6th. That the current of the Galvanic fluid produces a great alteration in the animal fluids; separates a great many of their principles, and produces this effect in a particular manner in urine.It is however much to be wished, that in addition to the knowledge already acquired in regard to Galvanism, some convenient method could be discovered of increasing or lessening its action on the animal fluids; by which means the advantages of the medical administration of this subtle agent would be rendered more certain and more effectual.
General reflections on the action and influence which Galvanism, considered in a medical point of view, exercises on the animal œconomy.
I shall not here speak of the variation in insensible perspiration, and of the increase of circulation, which, according to the observations of several physicians, are found to be produced by Galvanism. Similar phænomena, as is well known, take place during the administration of common electricity. I shall therefore confine myself to those effects which hitherto have been produced only by the action of Galvanism. I shall observe in the first place, that Galvanism, as already shown in the Experiments detailed in the Second Part, is capable of effecting a separation of the fluids, and even sometimes of protruding the fæcal matters from the body. In the case of the decapitated malefactor, I found that when the arc was applied to one ear and to the lips, a very sensible portion of saliva was discharged from the mouth. This observation was confirmed at Genoa on the head of an ox, and in several other places on the heads of sheep. The phænomenon of the extrusion of the fæcal matters from the trunk of an ox, by means of Galvanism, wasobserved also by Professor Mojon of Genoa, and his brother, to take place in human bodies. Considering the animal fluids separately, I have found that very great variations are produced in them by Galvanism. But before I give an account of the experiments which I made on this subject, I shall describe the apparatus I employed.
The animal fluid destined to be exposed to the action of Galvanism is put into a glass vessel (PlateIII.fig. 6.) covered by a wooden lid, having in it two holes equally distant from the centre. Two wires, one of brass and the other of plated copper, the upper extremities of which are bent into the form of a hook, pass through these holes in such a manner, that the lower extremities of them reach nearly to the bottom of the vessel, where they are bent at right angles, so that only a very small interval is left between them. The upper extremity of one is made to communicate with the bottom of the pile, and the other with the summit. In consequence of this arrangement the Galvanic fluid is obliged to traverse the animal fluid, by which means it exercises an action on it according to the distance of the wires, and by its action separates from its different strata sometimes one principle and sometimes another; and this secretion will be effected with more ease and in greater abundance, according as the action of the pile is stronger, and the capacity of the conductors more considerable.
EXPERIMENTI.
Having put into glass vessels four ounces of blood recently drawn from the vein of a person in good health, I left one of them exposed to the contact of the atmospheric air, and subjected the other to the action of the pile. In both these portions I observed a speedy coagulation of the crassamentum, and at the end of twenty-four hours the serous part was separated. The blood exposed to the action of the pile adhered so strongly to the two wires immersed in it, that it was difficult to separate them from the clot which was thus suspended in the aqueous fluid, but in the other vessel the clot remained at the bottom.
EXPERIMENTII.
I put two equal portions of bile, still warm, taken from the gall-bladder of an ox, into two glass vessels, exposed one of them to the contact of the air, and subjected the other to the action of the pile. After ten hours had elapsed, I observed that the bile in the latter had become so opake as no longer to afford a passage to the light; while the other portion, exposed to the atmosphere, retained its transparency and colour. I observed also a considerable disengagement of air, the nature of which I have not yet had an opportunity of examining.
EXPERIMENTIII.
I took four ounces of urine, voided by a man in good health, exposed it to the action of the pile, and at the end of twenty-four hours found that the greater part of its constituent principles was separated. A portion of them was collected around the wires in such a manner as to form cylindric bodies of a considerable diameter, of which the wires were the axes. As the mass of the attracted matters increased, a portion fell to the bottom by its own weight. The cylinders were soon entirely destroyed, and the substances which formed them were precipitated by the least shock given to the vessel. I repeated this experiment lately in Mr. Wilson’s anatomical theatre in Windmill-street; and I observed, at the end of eighteen hours, a great quantity of the moleculæ furnished by the urine adhering to the two wires. But at length, not being able to withstand the effect of its gravitation, it began to fall down, forming a sort of wedge, the apex of which was at the surface of the urine, and the base at the bottom of the vessel.
EXPERIMENTIV.
Instead of putting the urine into a common apparatus, if a glass syphon with two platina wires be employed (Plate III. fig. 5.), the urine becomes limpid on the one side, and turbid on the other. The substance detached from the urineafterwards appears in the form of flakes, which are attracted by the platina wires. I observed this phænomenon for the first time in the company of those celebrated chemists Fourcroy and Vauquelin, while they were performing Galvanic experiments in their own laboratory.
EXPERIMENTV.
The substance above mentioned, which was precipitated to the bottom, when separated by filtration and dried, weighed about the fourth of a grain, and the fluid separated from it was of a greenish colour. On examining the earthy deposit of this urine, we obtained sulphate of lime by adding to it sulphuric acid.
EXPERIMENTVI.
Having exposed to the action of the pile, in the same manner, four ounces of urine voided by a person with jaundice, I obtained an earthy sediment, the weight of which was nearly equal to that above mentioned. The liquor separated from it was transparent, inclining a little to black. By the same chemical process I obtained sulphate of lime, though the sediment of the urine was somewhat dark, and afforded a portion of carbon and bile which inflamed in the fire.
EXPERIMENTVII.
Having repeated the above experiments with different kinds of urine, I observed in general, that Galvanism, by a peculiar attraction, separates from urine the sulphates and muriates united to a portion of the bile, and also to carbon, which in a great part are precipitated to the bottom of the vessel: the other part, which remains attached to the wires, exhibits a regular saline crystallization, of so singular a form that it seems worthy of becoming an object of further research to chemists.
The examination of urine voided by persons labouring under different kinds of disease, seems to be an object sufficient to excite the curiosity of physicians. To expose to the action of Galvanism artificial aëriform fluids, analogous to those which act a part in the animal œconomy, might also be attended with advantage. For this purpose it will be convenient to employ the apparatus represented inPlateIII.fig. 7, which was lately constructed, with great precision, by M. Dumoutier at Paris. The whole artifice consists in a vertical metal tube, which can be raised up or pushed down. It is furnished with a stop-cock, and the tub in which the apparatus is placed has another. If the inverted bell be filled with water, and connected, by means of the vertical tube, with the apparatus which is to supply the gas, on opening the lower cock, the water will descend in the bell,and its place be supplied by the gas intended to be subjected to experiment.
From all the observations hitherto made, there seems to be reason to conclude, that the effects produced on the animal œconomy by common electricity and by the Galvanic pile are different. The phænomena of artificial Galvanism give us some right to suppose, that a similar action is exercised by the Galvanic fluid circulating in the fluids and in the organs of living animals. In this point of view Galvanic researches may one day throw great light on the nature of secretion; and it may perhaps be found necessary, when remedies are administered, to take its influence into consideration: for it is possible that the action of these remedies in the animal œconomy may depend on the establishment of such an arc between the system of the nerves and that of the muscles, as may not alter the natural state of the Galvanic fluid proper for the constitution of the individual to whom these remedies are administered. All this however is mere conjecture, and must be classed with many other things in the theory of Galvanism which are still involved in obscurity, and which we can hope to see explained only by new researches and new experiments.
Taking a general view of this Third Part, I must observe that the administration of Galvanism, when the above experiments are carefully examined, seems to appear in a muchmore advantageous point of view than before. I have indeed proved:
1st. That Galvanism, on many occasions, exercises an influence different from that of common electricity, and that it may be administered in various cases with great ease and safety.
2d.That the action of Galvanism manifests itself by a sensible attraction between the nervous and muscular parts; which seems to confirm the hypothesis of Humboldt, who supposes a Galvanic atmosphere peculiar to these parts when in a state of perfect vitality.
3d.That the strong impression made by Galvanism on the brain seems to explain its power on the organ of hearing; and therefore the physicians of Berlin, and other parts of Germany, are entitled to great praise for their researches on this subject.
4th. That though medicine is capable of affording considerable aid in cases of drowning and of asphyxia, it presents us with no means so powerful as Galvanism. The experiments made at London, Jan. 17, 1803, on the body of Forster, executed for murder, have fully convinced me of the activity of this stimulant.
5th. That in cases of melancholy madness, when otherremedies fail, Galvanism may be employed with the greatest hopes of success, provided the disease does not proceed from a vitiated constitution, or a general derangement in the animal machine.
6th. That the current of the Galvanic fluid produces a great alteration in the animal fluids; separates a great many of their principles, and produces this effect in a particular manner in urine.
It is however much to be wished, that in addition to the knowledge already acquired in regard to Galvanism, some convenient method could be discovered of increasing or lessening its action on the animal fluids; by which means the advantages of the medical administration of this subtle agent would be rendered more certain and more effectual.