SPEC. I. The expe experiment, and the experiment, as he conceived, fully GEN. I. established his pre-conceived opinion: and gave proof Apostema that the pus of an abscess does not act as a solvent. commune. This conclusion of his only shows how difficult it is for Common Aposteme. the most honourable mind, when biassed by a favourite hypothesis, to weigh with an even hand the evidence that lies before it. "To see", says he, "how far the idea was just, that dead animal matter was dissolved by pus, I put it to the trial of experiment, because I could put a piece of dead animal matter of a given weight into an abscess, and which could at stated times be weighed. To make it still more satisfactory, a similar piece was put into water, kept to nearly the same heat. They both lost in weight; but that in the abscess most. And there was also a difference in the manner, for that in the water became soonest putrid."* There is nothing in animal chemistry, strictly so called, that decomposes animal substances so rapidly as putrefaction. And yet in the present instance the pus of an abscess evinced a more active decomposing power than the fluid of water, though aided by the accessories of putrefaction. It is not very wonderful that Mr. Hunter, though regarding this result as in his favour, should not be disposed to "rely on its accuracy", and he refers us, therefore, for a further proof to a more competent experiment of Mr. (now Sir Everard) Home, Experiment which consisted in immersing a portion of muscle weighing exactly one drachm, "in the matter of a compound fracture in the arm of a living man, and a similar portion into some of the same matter out of the body; also a third portion into fluid calf's-foot jelly, in which the animal substance was pure, having neither wine nor vegetables mixed with it. These portions of muscle were taken out every twenty-four hours, washed in water, weighed, and returned again." The result of this experiment is still more in favour of the solvent power of pus than the preceding. At the end of forty-eight hours there was indeed no great dif * On Blood, &c. Part 11. Ch. v. p. 419. riment apparently at variance conclusion. with his of Home. This experiat variance with ment alike Hunter's conclusion. GEN. I. SPEC. I. Apostema commune. Common aposteme. Second use of pus to assist in the process of granulation. Confirmed ments of Bauer: ference, as the muscle in the abscess was reduced to thirty-eight grains, and that in the other two fluids to thirty-six. But from this period to ninety-six hours the muscle in the jelly continued the same, while that in the abscess was reduced to twenty-five grains; and that in ths exposed pus dissolved; the power of putrefaction, as Mr. Hunter observes, being in this last case superadded to that of the pus itself. We hardly stand in need of other experiments. The solvent power of pus above that of water, of animal jelly, and hence we may conclude of animal fluids in general, is sufficiently established by the very evidence that is advanced in opposition to this power. And it should hence seem that one at least of the direct uses of pus is to reduce, surface after surface, the dead animal matter which is exposed to its action to that state in which it may be rendered fit for absorption, and at the same time conveyed to the mouths of the absorbent vessels. But I have for many years thought that it has also another equally important use; that, I mean, of assisting in the process of granulation; and a late article of Sir Everard Home in the Philosophical Transactions, containing the observations of Mr. Bauer upon the germination of plants, and his application of those observations to the growth of the new vessels in animals †, seems, if not to have settled the question, at least to have very considerably favoured this view of it. Having sown a quantity of wheat for the purpose of by experi- noticing the changes which occurred from the first, Mr.. Bauer took up every day several grains or plants for examination till they were ripe; and in the course of his attention, was much struck with the rapid increase of the tubular hair of the root of a young plant of wheat in its earliest stage of vegetation; and, fixing his view entirely to that part of the plant, he observed small pustules • Dissertation on the Properties of Pus, p. 32. + Phil. Trans. 1818, p. 180-194. GEN. I. SPEC. I. Apostema, aposteme. of a slimy substance arising under the epidermis in the surface of the young root; and in a few seconds a small bubble of gass bursting from the root into the slimy matter commune. which it extended in a moment to the length the hair Common was to acquire; when the slimy matter surrounding the gass immediately coagulated and formed a canal. He repeated his observations on another plant, whose pubescence consisted of a jointed hair, and observed the same effect; a bubble issued from the young stalk, and extended the slimy mucus to a short distance, forming the first joint, which immediately coagulated and became transparent; and at its extremity a new pustule of the same slimy matter accumulated, into which, in a short time, the gass from the first joint rushed: and thus, in a moment, a second joint was formed. In the same manner, he observed, the formation of the hairs of ten or twelve joints take place. Impressed with the importance of these facts, Sir and Home. Everard Home immediately began to inquire how far the same course is pursued in the production of new animal matter. He first ascertained by experiments of Mr. Brande, already noticed in the Proem to the second class of this work *, that blood in a state of circulation contains a considerable proportion of air, which, in the process of its coagulating, escapes in the form of carbonic acid gass, and in its escape produces bubbles as in the slime of plants; and that it escapes equally from the coagulating blood of veins and arteries, from effused serum, and from pus. And in pursuing the subject he found that, on the coagulation of a drop of blood placed in the field of a microscope, an intestine motion occurred, and a disengagement of a something took place in different parts of the coagulum; beginning to show itself where the greatest number of globules were collected, and from thence passing in every direction with considerable rapidity through the serum, but not at all interfering with the globules themselves, which had all discharged their * Vol. I. p. 475. GEN. I. SPEC. I. Apostema commune. Common aposteme. Other ex periments necessary: colouring matter. Wherever this extricated colouring matter was carried, a net-work immediately formed, anastomosing with itself on every side through every part of the coagulum. When the parts became dry, the appearance of a net-work remained unaltered. In some instances bubbles were seen to burst through the upper surface of the coagulum; this however did not prevent the ramifications that have been described from taking place. "When this happens," continues Sir Everard, "in living animal bodies, from whatever cause, and in whatever circumstances it takes place, no difficulty remains in accounting for its afterwards becoming vascular, since all that is necessary for this purpose is the red-blood being received into the channels of which this net-work is formed." He next proceeded to the subject immediately before us. "As the globules of pus" says he," are similar to those of blood, I made experiments upon the fluid in which they are suspended, and found inspissation produce the same effect on it as coagulation does on the other; that a similar net-work is formed and apparently by the same means, since if pus be deprived of its carbonic acid gass (of which it contains a large quantity) by exhaustion in the air-pump, no such network takes place." Additional experiments are still necessary upon this interesting subject; but so far as they go, they seem very but the pre- clearly to indicate the important and double use to which is subservient; that it acts as a solvent upon the pus dead matter, preparing it for absorption, and as a fomes for granulation and the production of new vessels. sent nearly decisive. No incongruity in these two qualities in hering in the same substance. Nor let it be observed in opposition to this conclusion that we are thus endowing it with incongruous and contrary qualities; and that if it be erosive in the one instance it cannot be nutrient in the other; for the animal economy presents us with various examples of like effects, contrary indeed but not contradictory, produced by one and the same secretion on dead and on living matter, for which we need go no further than to the very common operation of the gastric juice; which, while the most pow GEN. I. SPEC. I. Apostema Common erful solvent of dead animal matter in the whole range of animal chemistry, is a healthy stimulant to the living stomach, and even to other living organs; and has suc- commune. cessfully been applied externally for this purpose by sur- aposteme. geons, to weak and ill-conditioned ulcers, and employed Illustrated by physicians as an internal tonic in cases of dyspepsy by the qualities of gasand cardialgia. tric juice. SPECIES II. APOSTEMA PSOATICUM. Psoas Abscess. PAIN AND TENSION ABOUT THE LOINS, SHOOTING DOWN THIS is one of the most lamentable diseases we can ever GEN. I. Primary seat of the use disease diffi be called upon to attend. It commences insidiously, and at the same time in parts so deeply seated as to render it very difficult to determine the place of its origin; and hence the psoas muscle itself, the cellular substance determined. interposed between the peritoneum and the loins, the lymphatic glands near the receptaculum chyli, and the lumbar vertebræ have been pitched upon by different writers. It is probable that most of these have formed the primary seat of affection in different cases, and that the inflammation has subsequently spread to one or more of the other parts: and hence, assuming no inconsiderable degree of latitude, M. Chaussier denominates the disease FemoroFemoro-Coxalgie. The pain at first is by no means violent, and the patient thinks lightly of it; it is sometimes felt in the back rather lower than the region of the kidneys; and sometimes as low down as the thigh. From coxalgie of Chaussier. Progress of the disease. |