1847.] The Muscular Electric Current. 515 better preserved, as the liquids remain longer without mixing. Poiseuille has also shown that endosmose ceases to take place in a membrane after a certain time of action, but that we may restore to the membrane this property by submitting it to the action of other liquids. The most remarkable fact discovered by Poiseuille is that of the influence exercised by hydrochlorate of morphia. This body added to saline solutions weakens very considerably the endosmose from the serum to the solution; and ultimately changes the direction of the current. This fact has been confirmed by Dr. Bacchetti. How can we make an entire abstraction of this fact in the explanation of the action of morphia and the preparations of opium in diarrhoea, and of the constipation which they produce ?"" The Muscular Current.-In the paper on the muscular current, presented by Matteucci to the Royal Society and printed in their Transactions, the results obtained from his different experiments are thus summed up. "In the first place, the intensity and duration of the muscular current are independent of the nature of the gas which envelops the muscular pile. Secondly, this current, as I have already shown from the commencement of my researches, is altogether independent of the cerebro-spinal nervous system, and the circumstances which exercise a marked influence upon its intensity are respiration and the sanguineous circulation. Thirdly, those poisons which seem to act directly upon the nervous system, have no influence upon the muscular current; among these I would mention hydrocyanic acid, morphine and strychnine. Fourthly, sulphuretted hydrogen has a marked influence in diminishing the intensity of the muscular current. Fifthly, the intensity of the muscular current varies according to the temperature in which the frogs have lived a certain time; it is needless to observe that this result is not discoverable except in those animals which, like the frog, necessarily take their temperature from that of the medium in which they live. Sixthly, the intensity of the muscular current increases in proportion to the rank the animals occupy in the scale of beings, while the duration of this current, after the death of the animal, is in an exactly inverse ratio. "Comparing these conclusions with those generally admitted by physiologists, and drawn from a great number of experiments on the vital properties of muscles, it is impossible not to perceive that the property of the muscles, immediately connected with the muscular current, is that which Haller calls irritability, and which at the present day, I believe physiologists designate by the name of organic contractility, or simply contractility." Our readers will not fail to perceive that the conclusions drawn by Matteucci from his experiments are opposed to the views of Dr. Marshall Hall. The Italian Professor regards the irritability of muscular fibre as inherent; whereas Dr. Hall considers it as derived from what he calls the true spinal system. "With regard to the manner of representing the origin of the muscular current," says Matteucci, "I find, in my present experiments, a confirmation of the opinion I set forth in my preceding ones. The chemical action which goes on in the nutrition of the muscle, principally that which takes place in the contact of the arterial blood with the muscular fibre, is in all probability the source of this electricity in the muscles." Some of the recent investigations of Liebig have reference to the origin of the muscular current. The celebrated Giessen Professor has at last succeeded in demonstrating the existence of free lactic and phosphoric acids in the muscles of animals. He thinks that his results explain the quick re-action of the muscles," and he adds that, now that we know that there exists, in so large a portion of the body of animals, an acid liquor, which is only separated from an alkaline fluid (the blood and the lymph) by very thin membranes, we may, I think, explain several electrical phenomena observed by Matteucci and other physiologists upon the bodies of dead (and living) animals." (See Chemical Gazette, Feb. 1, and Feb. 15, 1847; also Comptes Rendus, Jan. 18th, 1847.) The Proper Current of the Frog.-In our review of Matteucci's Traité des Phenomenes Electro-physiologiques (Medico-Chirurgical Review for April, 1845), we protested against Matteucci's assumption that the frog had any peculiar electric current; and we did so because it appeared to us that the assumption was in opposition to every thing then known respecting the organization and physiological relations of animals; and we observed that we could not " for a moment admit the probability of the frog possessing a peculiar electric current, unendowed as this animal is with any peculiar organs or electric apparatus." And we further stated our confident belief that, "whatever currents may be detected in the frog, the same will be found to exist, in some degree of intensity, in other animals.” The accuracy of our view is now fully established by the more recent investigations of Matteucci himself, detailed in his second Memoir, subsequently published in the Philosophical Transactions. From the additional experiments, referred to in the Memoir just quoted, made with the view of clearing up certain points which had been left in an unsettled state, in the Traite, Matteucci concludes, "That the proper and the muscular current are in general subjected to the same laws, and that both these currents vary in the same sense, under the same circumstances." Feeling the importance of solving the question why the proper current should belong exclusively to the frog, Matteucci next directed his attention to this point, and arrived at the following "Generalization of the fact of the proper current of the frog; the current is directed within the muscle from the tendon to the superficies. "It remained for me to extend this fact to its operation upon the muscles of warm-blooded animals, and the experiments accorded in such a manner as to leave no possible doubt." His experiments were made on fowls, pigeons, rabbits, and dogs; and their results were such as to establish the correctness of the position we took up in the review before quoted; and we therefore claim for ourselves the credit, small though it be, of having denied the speciality of the proper current in the frog, and of having asserted our belief of its universality in animals. In his Leçons, Matteucci thus clearly states the conclusions at which he has recently arrived. "Recently, by studying more attentively the proper current, I have satisfied myself that it is a phenomenon which appertains to all animals. Here is the enunciation of the fact; in every muscle endowed with life in which the tendinous extremities are not equally disposed, there exists a current directed from the tendon to the muscle, in the interior of the muscle. All animals have muscles in which one tendinous extremity is narrower than the other; which at one part forms a kind of cord, and at the other becomes broader and ribbon-like. In the 1847.] Induced Contractions. 517 frog and many other animals, the gastrocnemius has this character: in birds, the pectoral muscle presents this arrangement. When we form a pile with these muscles, we find that a current circulates in the muscle, from the tendinous extremity to the muscular surface. "In arranging this pile, we must carefully avoid exposing the internal part of the muscle, and we must especially place one element in contact with another, in such a manner that the tendinous extremity touches the surface of the muscle, and never the interior; indeed, the latter ought to be as far as possible from the tendon. Without this precaution, there will be, in the circuit, the muscular current, which, being directed from the interior to the surface, would have a direction precisely the reverse of that of the proper current. Having thus ascertained the conditions on which the proper current depends, I think that I may generalize its origin and connect it with the muscular current. This community of origin is principally demonstrated by the identity of action which the different circumstances that modify the organism and the life of animals exercise upon the muscular current. In fact, whether the current be muscular or proper, the action exercised on it by heat, narcotics, sulphuretted hydrogen, and the degree of integrity of the nervous system is the same. "Anatomists have lately demonstrated that the elementary muscular fibres are immediately continuous with the tendinous fibres, and that the sarcolemma which invests the muscle, ceases abruptly where the tendon begins. We may, therefore, with some probability, consider the tendon as being in the same electric condition as the interior of the muscle; and, therefore, when we form by means of a good conductor, a circuit or communication between the tendon and the sarcolemma, we put into circulation a portion of the muscular current.” On Induced Contractions.-In our review, before referred to, of Matteucci's Traité, we noticed the physiological phenomenon produced by a muscle in contracting, and proposed to call it electric sympathy; Matteucci now terms it induced contraction, or muscular induction. The subject, though important to the physiologist, is very obscure. In his later memoir on it, inserted in the Philosophical Transactions, Matteucci first examines. the question whether electricity is evolved during the contraction of a muscle and concludes that it is not. After examining various physical theories of induced contraction, he concludes by admitting that "we cannot give a satisfactory explanation of the phenomenon of induced contraction by recurring to electricity or any other known causes," and infers that "induced contraction is only a new phenomenon of nervous force." We must now conclude our account of Matteucci's Lectures and Memoirs. In noticing the former we have been obliged to limit our extracts and observations to a few only of the subjects treated of. But, as we have enumerated the various topics which the author successively considers, our readers will be able to form a fair idea of the extent and scope of this most interesting and instructive work; and we trust that the extracts which we have made from it will justify our opinion of its highly meritorious character. It is alike valuable and interesting to the general reader and the professional man,-to the natural historian and natural philosopher, to the physiologist and the practical physician. With the exception of Magendie's Lectures (published in Paris in 1842 in 4 volumes 8vo.), we are unacquainted with any other modern work, besides that of Matteucci, which is expressly devoted to the physical phenomena of living beings, yet the subject is of growing importance, and loudly calls for further investigation. One reason why its literature is so scanty is, perhaps, the paucity of persons who combine, in one individual, a sufficient acquaintance with both physical and physiological sciences, to qualify him for the investigation: physics and physiology being usually regarded as entirely different branches of study. In the case of Magendie we have an instance of a physiologist successfully pursuing physical researches with the view of applying physical agencies to the explanation of physiological phenomena. Matteucci, on the other hand, is a natural philosopher, a professor of the physical sciences, who has extended his investigations to organized bodies, in order to ascertain whether many of the phenomena presented by living beings, and called vital, may not be, in reality, due to physical influences. The subject, therefore, has been regarded by those two eminent philosophers from opposite points of view; and the work of the one is consequently not a substitute for that of the other. Some of our readers may perhaps be glad to learn that an English translation of this work, made under the superintendence of, and annotated by, Dr. Pereira, has been announced, by Messrs. Longman and Co., for immediate publication. I. A MANUAL OF THE PRINCIPLES AND PRACTICE OF OPHTHALMIC MEDICINE AND SURGERY. BY T. Wharton Jones, F.R.S. Small 8vo. pp. 570. Churchill, 1847. II. ON CATARACT, ARTIFICIAL PUPIL, AND STRABISMUS. By F. III. ANNALES D'OCULISTIQUE. Tom. XVI. XVII. 1846–7. V. PAPERS ON INFLAMMATIONS OF THE EYE. By A. Jacob, M.D. WE had hoped to have had M. Desmarres' work upon ophthalmic medicine in our hands before this; but the publications above cited will, in the mean time, furnish us with some interesting information to place before our readers. Mr. Jones' " Manual" is a very elaborate compilation, and will, in this age of condensing, epitomising, and manualizing, doubtless occupy the foremost place. To our own taste it is, however, needlessly extended in its earlier portions. The directions for examining the eye are frequently too anticipatory of the descriptions of its diseases, and are minuter than necessary for those, as we hope all do, who avail themselves of opportunities of practically studying this important subject, which, perhaps less than any other, is to be managed by books. Here the student has the opportunity, which so few other perverted conditions of the economy furnish him with, of seeing disease at its onset, during its various stages of pro 1847.] Examination of the Eyes of Children. 519 gress, and in its different effects. This facility of inspection has, however, been disadvantageous in one respect, that of encouraging a disposition to minute and fanciful division and subdivision of the various morbid appearances, which, conjoined with the jargonic vocabulary that has been invented for the purpose of indicating these, has well nigh converted into a difficult and repulsive study, that which is really in its natural simplicity very easy, and should be attractive. Mr. Jones has farther unnecessarily enlarged his book by a long description of the various phenomena of inflammation in general. Ably as we allow this is written, it is surely time a stop were put to the practice of writers upon special subjects taking it for granted that their readers are unacquainted with the most general principles of disease, and occupying space which should be otherwise filled, or better still spared altogether, with dissertations which find their proper place elsewhere. Among Mr. Jones' directions for examining the eye, that applicable to children seems to us a useful one. "For the examination of the eyes in children, especially when affected with intolerance of light and blepharopasmus, considerable management is required, and even some degree of gentle force. The surgeon is to seat himself on a chair with a towel, folded long-ways, laid across his knees. On another chair, on the surgeon's left hand, and a little in front of him, the nurse, with the child, sits in such a way that when she lays the child across her lap, its head may be received on the towel, and between the knees of the surgeon, and thus held steadily. The nurse now confines the arms and hands of the child, whilst the surgeon, having dried the eyelids with a soft linen cloth, proceeds to separate them by applying the point of the forefinger of one hand to the border of the upper eyelid, and the point of the thumb of the other hand to the border of the lower, and then sliding them against the eyeball, but without pressing on it, towards their respective orbital edges. This mode of proceeding obviates the eversion of the eyelids, which is so apt to take place under these circumstances. The eyelids being thus opened, they are readily kept so during the examination, by the command, which the points of the finger and thumb, resting against the edges of the orbit, have of their borders. By this means the whole front of the eyeball is exposed, but it often happens that, to avoid the light, the eye is spasmodically turned up, so that the cornea is in a great measure concealed. By waiting a few seconds, however, enough of it will in general come into view to enable the surgeon to judge of the state in which the eye is. Having completed this portion of the exploration, there is not much difficulty in so everting the eyelids as to ascertain the state of the palpebral conjunctiva.”—P. 14. We may commence with some account of The Ophthalmia. These Mr. Jones divides into four orders. O. Externa, Interna anterior, Interna posterior, and Panophthalmitis. The first of these is subdivided into Conjunctivitis, Sclerotitis, and Corneitis; the second, into Aquo-capsulitis, Iritis, and Crystallino-capsulitis anterior; the third, into Choroiditis, Retinitis, Vitreo-capsulitis, and Crystallino-capsulitis posterior; while the fourth (inflammation of the whole eye) is fortunate in constituting but the one order and genus. That inflammation may affect any of these textures is certain, but the practice among Ophthalmologists of describing its agency as so many isolated or separate diseases, has long seemed to us a most faulty one. This, joined to the innumerable modifications induced by diathesis detailed by other observers, renders the study of the subject |