« ZurückWeiter »
urine alkaline and hazy from phosphates, or if clear on excretion, heat caused their deposition; the addition of a little hydrochloric acid caused an effervescence like champagne; too much liquid, a bladder already filled with acid urine, or a disproportionate allowance of flesh, interfered with the success of the experiment. How often are those ill of chronic complaints who use a moderate diet, and with whom fruit is a useful and favourite article, troubled with hazy and alkaline urine, causing anxiety alike to themselves and their physi cian, which a little physiology does away with. In the simple chronic nephritis of Rayer, the chief symptom is the alkalinity of the urine; in no case was there a sectio cadaveris; and some of the cases recovered so quickly, as to justify a doubt as to the correctness of the diagnosis; although he inculcates careful dietetic treatment, it is evident from his work that the semiotic influence of fruit in small quantities was unknown to him. This article is not forbidden at La Charité, and friends of the patients often carry them some. In several of his cases the alkalinity of the urine seemed to depend on purulent admixture, and consequent rapid putrefaction; and in one it seemed to be kept up, if not produced, by the use of an alkaline saline water (Contrexeville.) The alkalinity of the urine has also been used by Prout as a diagnostic sign of certain spinal affections. These he divides into two great classes:-1st, Those arising from depressing emotions and weakening influences: and in these he recommends the use of fruit, and fluids containing malic acid, as cider and perry; to these, and not to any disease, our author refers the alkalinity of the urine. 2d, Injuries of the spine: our author states, that neither Rayer nor himself had ever been able to observe the urine alkaline in cases of injuries of the spine unless there were some existing or consecutive affection of the mucous membrane of the urinary passages, producing purulent admixture, hastening thereby the putrefactive changes in the urine. In the three cases detailed by Prout, two had stricture of the urethra, and the third retraction of the tes ticle, and a mucous sediment,-all bespeaking the existence of some such affection. A microscopical examination, by showing the exist ence or absence of pus cells in the urine, would have confirmed the diagnosis, or at once corrected it. How far inattention to diet may have led to error, cannot be specified. Prout also mentions, without explanation, what has been already referred to,-viz. That although alkaline urine, by copious secretion, be clear and bright, yet boiling causes it to deposit a phosphatic sediment, which falls without any such previous process, if the secretion be more sparing; the phosphates separate before the boiling point, and from their great specific gravity fall rapidly, and may thereby, as well as by their solubility in acids, be distinguished from the albumen found in Bright's disease.-Ibid, from Zeitschrift für Rationnelle Medizin.
On the Nature of Tetanus caused by Strychnine. By Professor HERMANN MEYER, Zurich.-The tetanic convulsions, which follow the exhibition of Strychnine, are well known; as also the fact that
these convulsions can be readily excited as reflex movements. The general use of strychnine in experiments on the nervous system is very much based on the knowledge of these facts, and invites to a discussion of the question as to the mode in which the tetanus originates. The following experiments were instituted for this
Exp. I. The crural nerve of a frog, suffering from convulsions induced by strychnine, was divided; these immediately ceased in the limb.
Exp. II. No convulsions took place in a limb, in which the nerve had been divided previous to the exhibition of the poison.
From these well known experiments, it follows that the originating cause of the convulsions must be sought for in the central parts of the nervous system. But the question ensues, does the tetanus originate from an affection of an individual portion of the central organ, or in an affection of every individual portion? The following experiments, also somewhat well known, tend to throw some light on the subject.
Exp. III. The brain was removed from a frog; tetanus ensued in the trunk.
Exp. IV. Brain and cerebellum removed, result as in the preceding.
Exp. V. Medulla oblongata removed; same result.
Exp. VI. Medulla oblongata divided; general tetanus ensued. Exp. VII. The spinal marrow was removed posterior to the giving off of the nerves to the anterior extremities; result as in the preceding case.
From these experiments, it follows that the origin of the tetanus is to be sought for in some cause common to all the central organs of the nervous system, The following experiments show what this cause is.
Exp. VIII. The posterior column of the entire spinal marrow was removed from a frog by means of a fine pair of scissors. solution of strychnine was then either exhibited by the mouth, or applied directly to the spinal cord. Convulsions occurred only in the jaws and eyes.
Exp. IX. The posterior column of that part of the cord giving off nerves to the posterior extremities was removed. Tetanus occurred only in the head and anterior extremities.
Exp. X. The same portion of cord giving off nerves to the anterior extremities was removed. Tetanus occurred only in the head and posterior extremities.
From these experiments, the author thinks himself entitled to conclude, that the presence of the motor nerves, even though uninjured, does not suffice to produce tetanus; but that there must also be an uninterrupted connexion of the sensory and motor fibres within the central part of the nervous system. The only motions, however, which we recognize as dependent on the sensory fibres, are those which we know to be the cause of reflex movements. The
above experiments, therefore, would lead to the conclusion, that tetanus caused by strychnine arises entirely from general reflex movements, and that the action of the strychnine not only excites the motor fibres, but goes to increase the necessary cause from which reflex movements arise. If this be true, tetanus must cease, even when the spinal marrow is uninjured, provided the conditions under which reflex movements arise are removed. In order to test this, the following experiments were instituted :
Exp. XI. The skin of a frog was rubbed over with strong prussic acid (30 per cent.,) so that the superficial peripheral extremities of the nerves were paralyzed. Strychnine was exhibited; no tetanus ensued, except when the animal was strongly shaken (thrown about, for example.)
Exp. XII. After laying open the spine of a frog, the posterior nervous roots were divided. Same result as above, or as when the posterior column of the cord was irritated with a needle.
Exp. XIII. The same experiment was repeated in a frog in which tetanus was present; it ceased immediately on division of the posterior roots, and only recurred under the conditions first stated.
From these experiments, then, it may be concluded, that tetanus arising from the action of strychnine originates entirely and alone from reflex movements produced by the strychnine exciting to increased action the primary cause of the reflex motions themselves.
The next question that occurs is, what is the primary cause of these reflex movements? Here, however, we find ourselves in the field of physiological controversy; as far as regards the question first considered, it is a matter of little moment how the controversy may be decided. It may be remarked, however, that tetanus induced by strychnine cannot be attributed to a general increased excitement of the nervous system. Were this the case, stronger contractions of the muscles dependent on the anterior cord laid bare in Exp. VIII. IX. and X. should have occurred rather before the administration of the poison than after it; but this was not the case. Other experiments, which require to be repeated, however, seem to show that the cause of reflex motion is to be sought for in the grey matter of the spinal cord, that the strychnine acts, therefore, by exciting to activity this grey matter, or rather the ganglionic in masses composed of it. These experiments are the following:
Exp. XIV. A needle was carefully passed down through the centre of the spinal marrow, of a beheaded frog, as far as the point where the nerves to the anterior extremities are given off, and then withdrawn. Strychnine was then administered. Tetanus occurred in the posterior extremities only.
Exp. XV. After laying open the spinal canal, the grey matter of the posterior half of the cord was destroyed as far as it gave off nerves to the posterior extremities. The movements of the latter
were little affected by the operation; but tetanus did not ensue after the exhibition of strychnine.-Ibid, from Ibid.
On the Origin of Solid Bodies in Synovial Cavities. By Dr. BIDDER.-The author had charge of a case of long standing swelling of the knee joint, which finally opened, allowing a quantity of granular matter to escape. The grains composing this matter were of a uniform size,-14" long, "" broad, 8" thick,--regular, flat-oval, clumped together in masses of variable size by a glutinous transparent fluid, present in but a very small quantity; they were highly elastic, presented no trace of a pedicle; their cut surface seemed homogeneous to the naked eye, and presented no trace of organization under the microscope; a chemical examination showed them to be composed of albumen. Mickel's opinion, so recently substantiated by Hyrtl, does not, therefore, hold good in every case; our author acknowledging its correctness in many cases, as well as the possibility of some cases arising from hydatids, (Dupuytren,) viz. those in which the bodies are possessed of a laminated structure. and have an internal cavity, notwithstanding that other distinctive marks may be lost, (vide Gluge. Anat. Mic.,) throws out another hypothesis as an explanation of their mode of origin in cases like the present, viz., that in certain cases an increased flow of blood, and consequent secretion of synovia, may force off the epithelium cells; that these subsequently increase, partly by endosmosis, partly by precipitation on their external walls; the peculiar life of the cell wall in certain cases altering the contents both with respect to colour and consistency, no membrane being perceptible under the microscope, may proceed from its stretched and thinned condition, from its being originally structureless, or from its homologation with its contents. The bodies examined by him consisted almost entirely of albumen, easily obtained from the synovia: their uniform size likewise presupposed their origin to have been from similar forms, endowed with similar capacities for life, conditions fulfilled by the epithelium cells. This theory can only bold good where the synovial cavities have an epithelial covering, which is wanting in bursæ mucosa, and mucous sheaths of tendons.-Ibid, from Ibid.
Note on the Exhibition of Sulphate of Quinina. By M. DONOVAN, Esq., M. R. I. A.-A student in medicine, M. Desvouves, some time since published, in the Revue Médico-Chirurgicale of Paris, a notice on an easy and certain method of removing all the bitterness of sulphate of quinina. In 1842, being at Martinique, attacked with an obstinate intermittent fever, he took sulphate of quinina which suspended the access. This medicine which, as we know, is very disagreeable to swallow, on account of its bitterness, was presented to him one day at the moment when he was going to take a cup of coffee for his breakfast.
He mixed 20 centigrammes (3 grains very nearly) of sulphate of quinina in a spoonful of coffee, and swallowed it, without perceiving any bitterness. The accession of the fever being interrupted, M. Desvouves discontinued the use of the medicine; but resumed it as the disease reappeared in 1843 and 1844; and he declares that, in ten trials, the bitterness of the sulphate of quinina was entirely destroyed by the coffee, and that its febrifuge agency was in no degree impaired.
Being afterwards in attendance on a child of six years of age, M. Desvouves administered 20 centigrammes of sulphate of quinina in the same manner: but the child not being accustomed to take coffee made on water, some spoonfuls of milk were added, without any complaints of the bitterness of the medicine, although it soon triumphed over the disease. In four days, 120 centigrammes (22 grs.) were taken, and the fever did not reappear. From this it might be inferred that coffee made on water, or mixed with milk, possesses the property of removing the bitterness of sulphate of quinina, without injuring its febrifuge properties.-(Jour. de Médecine de Mai, 1847, p. 204.)
Supposing for the present that all these are well-observed facts, it might be conceived that the tannic acid present in the liquid coffee would decompose the sulphate of quinina, forming tannate of quinina, which, being an insoluble salt, would have less taste than if it were in solution; but in this respect it would have no advantage over the sulphate itself.
Decoction of coffee contains tannic acid. If sulphate of quinina be mixed with cold decoction of coffee, no change takes place; the sulphate remains undissolved. But if the decoction be very hot, the sulphate dissolves and is decomposed; the tannate of quinina partly precipitates on cooling, and partly remains suspended, forming a muddy liquid.
If to some cold decoction of coffee, a little sulphate of quinina and a few drops of dilute sulphuric acid be added, solution takes place : but that the sulphate has been decomposed will appear by the deposition of copious clouds of tannate of quinina which soon make their appearance.
Such are the facts concerned; but none of them are of any avail, either in explaining or supporting the statement of M. Desvouves. I mixed cold decoction of coffee with sulphate of quinina, and swal lowed it; the taste was intensely bitter. I dissolved some sulphate of quinina in very hot decoction of coffee; the taste of this was equally bitter. I promoted the solution of the sulphate in cold decoction of coffee by means of two drops of dilute sulphuric acid; but the taste was as bitter as ever. This being my result, I forbear to theorise on the alleged destruction of the bitterness. The decoction which I used was of the usual strength made for the table. If intensely strong coffee disguise the taste of the sulphate, it must be by decomposing it, and forming the insoluble tannate.