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are parallel. An argument in favour of the existence of oxygene in oxymuriatic gas, may be derived by some persons from the circumstances of its formation, by the action of muriatic acid on peroxides, or on hyperoxymuriate of potash; but a minute investigation of the subject will, I doubt not, shew that the phenomena of this action are entirely consistent with the views I have brought forward. By heating muriatic acid in contact with dry peroxide of manganese, water I found was rapidly formed, and oxymuriatic gas produced, and the peroxide rendered brown. Now as muriatic gas is known to consist of oxymuriatic gas and hydrogene, there is no simple explanation of the result, except by saying, that the hydrogene of the muriatic acid, combined with oxygene from the peroxide to produce water.' p. 31.
These views of the subject, Dr. D. thinks, are confirmed by an experiment which appears to prove, that pure oxymuriatic gas is incapable of altering vegetable colours : and he supposes that its operation in bleaching, depends entirely on its property of decomposing water, and liberating its oxygene. He exposed litmus paper which had been gently heated, and afterwards still farther dried by the agency of dry muriate of lime, to oxymuriatic gas which had been also dried by muriate of lime: but no change of colour took place, and there was scarcely a perceptible alteration in several days. Dried litmus paper, however, exposed to some gas which had not been acted on by muriate of lime, became instantly white; paper which had not been dried, exposed to dry gas, was also whitened, but
ore slowly. It has been generally understood, that oxymuriatic gas at a low temperature may be condensed and and chrystallized : but Dr. D. finds this not to be the case. Water, containing it in solution, freezes more readily than pure water ; but gas which has been dried by muriate of lime, undergoes no change at 40° below 0° of Farenbeit.
Dr. D. atter pted to decompose the boracic phosphoric acids by oxymuriatic gas --but without success; and the few experiments which he made, on the combination of the oxymuriatic compounds with each other, or with oxides, did not present any remarkable phenomena.
Dr. Davy concludes this lecture with some suggestions, relative to the nomenclature of the oxymuriatic compounds. Having formerly proposed the name of chlorine or chloric gas,-a name founded on its colour-lie' now proposes that its compounds shall be designated by the name of the base with the termtinaion of ane, as argentane, stannane, &c. And when the compound shall consist of two or more proportions of inflammable matter for one of gas, or tw@ re to offer and
prefer retain literation whic
or more of gas with one of inflammable matter, he proposes that the vowels shall be prefixed in the order in which they occur in the alphabet, when the inflammable matter predominates, and after the name when the gas is in excess. We must confess that, to us, this appears to savour of very unnecessary innovation, and if we might venture to offer an opinion in opposition to such high authority, we should prefer retaining its old name only discontinuing the term acid, an alteration which Dr. D. has himself adopted in the present lecture,) simply calling it oxymuriatic gas. A nomenclature founded on theoretical principles may be liable to considerable objections : but as that proposed by the French chemists is now universally adopted, and is interwoven with the whole body of chemical science, we think its principles would be less violated by continuing the name of oxymuriatic gas,-the alterations would be fewer and more simple, and would harmonize better with established principles. The term oxymuriatic gas is a very correct expression of its most prominent character, as the acidifying principle in the muriatic acid; a name which 10 one, we presume, would wish to change into one derived from hydrogene, or any of its modifications. The term murioxide might express its combinations with the metals or other inflaminable bodies. We should then have the murioxide of potassium, of sodium, silver, tin, sulphur, &c.; and to this might be prefixed the terms proposed by Dr. Thompson, and now geverally adopted, to express the different degrees of oxidation.
II. The Croonian Lecture. On some Physiological Re. searches respecting the influence of the brain in the action of the heart, and on the generation of animal heat. By M. B. C. Brodie, F. R. S. Read December 201810.
Mr. Brodie having found, as Cruikshank and others had done before him, that, after the division of the spinal marrow, or the total removal of the head, (the bloodvessels being secured by, a ligature,) the heart still con. tinued to contract, and to circulate dark coloured venous blood; thought it probable that the circulation might be kept up some time longer by the action of a pair of bellows, in imitation of natural respiration. L'nder these circumstances, the heart continued to contract apparently with as inuch strength and frequency, as in the living animal; the blood in the pulinonary veins and aorta, was of the usual forid colour of arterial blood; and of the venous colour in the pulmonary artery and venæ cavæ. VOL. VII.
The most prominent circumstance in the experiment, however, was the gradual dininution of temperature, notwithstanding the continuance of the circulation : and this diininution was found to proceed faster than in another animal newly killed and exposed to the same atmosphere. The following table shews the corresponding temperatures of two full grown rabbits, of the same colour and size. The artificial respiration was performed about 3 times in a minute, and the contractions of the heart, during the first hour, were 144 times in the same period.
Rabbit with artificial respiration.
Therm. in the Therm. in the Therm. in the Therm. in the
yeture of have had Now chicer sec,
Though particular attention was paid, in most of the experiments, to the state of the bladder, no urine appeared to have been secreted, in any of them; and it is highly probable that all the other secretions were also completely suspended. Now this circumstance alone, we con. ceive, must have had very great influence upon the temperature of the animal : and it is generally admitted by physiologists, that the actions of the various secretory organs form one very abundant source of that caloric which, in warm blooded animals, keeps their temperature so much above that of the atmosphere in which they live i-and there is pretty strong proof that these actions cannot go on without the influence of the nervous system. But besides this, no notice, it seems, was taken of the production of carbonic acid, in these experiments: and the only information which we find on this part of the subject, is contained in a note at the conclusion of the volume, stating that carbonic acid was produced in one experiment in which 'oxygene was used. But as the proportion of carbonic acid was not determined, the quantity which might exist
5, which could regard to derivation are culle case
in the lungs, previous to the death of the animal, may be sufficient to have produced the precipitation of the lime, which took place on passing it through lime water.
III. On the expansion of any functions of multinomials. By Thomas Knight, Esq. Communicated by Humphry Davy, Esq. L. L. D. Sec. R. S.
This ingenious paper is not susceptible of abridgement. It seems to have been suggested by a perusal of M. Arbogast's abstruse work, •Du calcul des Dérivations,' in which, as is well known to most mathematicians, the expansion of multinomial functions is very fully treated. But Mr. Knight has traced some new and rather remarkable theorems, which could not easily have been found by Arbogast's methods. In regard to the functions of one simple multinomial, his rules of direct derivation are the same as those of that author. But in the more difficult cases of double and triple multinoinials, &c. or functions of any number of them, he presents new and expeditious methods which are so demonstrated as to be easily kept in memory, by those who are fond of such researches. His notation, too, is much simpler than M. Arbogast's, and gives his method a great advantage over that in point of conciseness ; though we think he will be able, should he pursue these rese. rches, to give it still greater simplicity and freedom from ambiguity.
IV. On a case of nervous affection cured by pressure of the carotids; with some physiological remarks. By C. H. Parry, M. D. F. R. S. Read December 20, 1810.
This case affords a very complete illustration of an ingenious theory of some morbid affections, usually called nervous : it is proposed by Dr. Parry, and appears to have been the result of careful and attentive observation. He was first led to conclude that many of the symptoms in question arise from a violent impulse of blood into the vessels of the brain, from a very interesting case which occurred, to bim in 1786, and which was published in the memoirs of the Medical Society of London in 1788. And he states that a mode of practice conformable to this principle, has enabled him to relieve a great number of nervous maladies, which had resisted the usual means of cure.
The subject of the present communication, was a lady more than 50 years of age, who became indisposed from being chilled by sitting a considerable time in a room
without fire, in the month of February, 1803. She en. deavoured to warm herself by exercise within doors, but in vain. The chilliness continued several hours; and, during this period, a sense of numbress seized the left side, with a momentary deafness, but without any pain or giddiness of the head, or any diminution of the other senses. After the deafness went off, the sense of heariog on the left side became more acute than natural ; and there was a sense of rushing-a tingling in the fingers of the left hand, which led her to conclude that "the blood went too forcibly there." In about six weeks, the numbness extended itself to the right side ; and she began to have occasional violent flushings of the head and face, even while her legs and feet were cold, together with a rushing noise in the back of the head, especially in hot weather, or from any cause producing increased temperature. These sensations were followed, some time afterwards, by convulsive twitchings or vibrations of certain portions the flexor muscles of the fore 'arm and of the deltoid on the left side, which were increased in frequency and force by any thing which heated or agitated the patient. The convulsive motions were constant when the muscles were in a state of relaxation ; and were usually about 80, in a minute. The pulsation in the carotids was very full and strong, and they appeared dilated for about half an inch in length, the canal above and below being of the natural size. Dr. Parry found, that strongly compressing the right' carotid artery, uniformiy stopped all these convulsive motions; while pressure on the left had no apparent influence upon them. He naturally attributes the cessation of the diseased action to the interruption of the flow of blood to the head; and concludes from this, and from many similar facts, that irritation of the brain, from an, undue impulse of the blood to that organ, is the common, though not the oniy cause, of spasmodic and nervous affections. Art. VI. Short Discourses, to be read in Families. By William Jay. . Vol. III. 8vo. pp, 474, Williams, Hatchard, &c. 1811. W HILE many volumes of sermons have been published
for the use of families, it may be safely affirmed that very few have been composed for that purpose. Indeed, the materials of which the greater part of such works con. sist, as well as the general cast of the composition, make it a matter of doubt, whether the authors of them have ever endeavoured to form a just or adequate conception of