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with his conclusion.

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

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, The expestrictly so called, that decomposes animal substances so

riment ap

parently at rapidly as putrefaction. And yet in the present instance variance the pus of an abscess evinced a more active decomposing cong 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 hę 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 weigh

ion of much

of Home. ing 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 This experi

ment alike the solvent power of pus than the preceding. At the at variance end of forty-eight hours there was indeed no great dif- wit


conclusion. • On Blood, &c. Part 11. Ch. v. p. 419. .

commune. Common

Gen. I. ference, as the muscle in the abscess was reduced to Spec. I.

thirty-eight grains, and that in the other two fluids to Apostema

thirty-six. But from this period to ninety-six hours the

muscle in the jelly continued the same, while that in the aposteme.

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 Auids 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. Second use But I have for many years thought that it has also anof pus to assist in the other equally important use; that, I mean, of assisting process of in the process of granulation ; and a late article of Sir granulation.

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 t, seems, if not to have settled the question, at least to have very

considerably favoured this view of it. Confirmed Having sown a quantity of wheat for the purpose of by experi

noticing the changes which occurred from the first, Mr. ments of

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. Trang. 1918, p. 190-194.




of a slimy substance arising under the epidermis in the Gen. I. surface of the young root; and in a few seconds a small

Apostema, bubble of gass bursting from the root into the slimy matter 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

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commune. Common aposteme.

Gen. I. colouring matter. Wherever this extricated colouring Spec. I.

matter was carried, a net-work immediately formed, Apostema

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 net

work takes place.” Other ex- Additional experiments are still necessary upon this periments

interesting subject; but so far as they go, they seem very necessary : but the pre- clearly to indicate the important and double use to which sent nearly pus is subservient; that it acts as a solvent upon the decisive.

dead matter, preparing it for absorption, and as a fomes for granulation and the production of new vessels.

Nor let it be observed in opposition to this conclusion

that we are thus endowing it with incongruous and conNoincon- trary qualities; and that if it be erosive in the one ingruity in

stance it cannot be nutrient in the other; for the animal these two qualities in- economy presents us with various examples of like effects,

contrary indeed but not contradictory, produced by one same sub

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



erful solvent of dead animal matter in the whole range Gen. I.

Spec. I. of animal chemistry, is a healthy stimulant to the living

8 Apostema stomach, and even to other living organs; and has suc- commune.

Common 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 qua

lities of gasand cardialgia.

tric juice.



Psoas abscess.




This is one of the most lamentable diseases we can ever Gen. I.

SPEC. II. be called upon to attend. It commences insidiously, and at the same time in parts so deeply seated as to ren- seat of the der it very difficult to determine the place of its origin; uitse be

disease diffiand hence the psoas muscle itself, the cellular substance determined. interposed between the peritonæum 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-Cocalgie. The pain at first is by no means vio

incoxalgie of lent, and the patient thinks lightly of it; it is sometimes Progress of felt in the back rather lower than the region of the kid- the disease. neys; and sometimes as low down as the thigh. From


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