of the skin is more severe and more prolonged, uric acid is formed in larger quantities, and the soda of the tribasic phosphate of soda then yields to the uric acid, and the urate of soda is formed. The presence of this powerful animal irritant in the blood gives rise to great constitutional excitement, under which the oxidation of tissue takes place with greater rapidity than perfection; in other words, under this highly excited vascular action a portion of the products of oxidation are carried into the circulation before the process is completed, and fresh urate of soda formed; thus the morbid matter is, under this increased vascular excitement and oxidation, constantly being renewed. In gout, imperfect oxidation of the blood is the result of repletion; that imperfect oxidation also leads to the formation of uric acid, and subsequently of the urate of soda in excess; but a life of inertia and indulgence, while engendering this repletion, has also induced an impure condition of the blood, on which this powerful animal irritant is incapable of producing the same stimulating influence that it does in rheumatism, where the blood was previously in a state of vital purity.

The indications of treatment are in both diseases the same as far as relates to the object to be attained-perfection of oxidation. In rheu

matism, at all events acute rheumatism, this perfection is to be attained by checking the rapidity with which it is carried on. In gout, on the other hand, our whole treatment is directed to the attainment of more perfect oxidation, by promoting its rapidity.

Many circumstances concur to induce us to believe that the peculiar symptoms of rheumatism are attributable to the presence in the blood of an unnatural and morbific matter, and that that morbific matter is the urate of soda. In the first place, it is evident, from the constitutional symptoms preceding the local ones, that they are not due to the local affections; secondly, the local symptoms are not fixed and permanent, but shift from joint to joint, and from one fibrous structure to another, as evinced by the phenomena of metastasis; thirdly, the symmetrical tendency which is so remarkably evinced in this disease, which was first pointed out by Dr. Budd, is strongly corroborative of the dependence of many of the symptoms of this disease on the existence of a poisoned condition of the blood; fourthly, the copious formation and deposition of urates in the urine contemporaneously with the disease, and their absence on the cessation of the symptoms, together with the, in some respects, striking resemblance of the symptoms to those

of gout, which depends on the existence of the same morbific matter, generated under different circumstances, and in an opposite state of the blood. To which may be added the fact, that the two diseases sometimes assimilate each other so closely, as we see in rheumatic gout; the symptoms of either disease preponderating according to the degree and extent to which the vital purity of the blood has been impaired by mal-assimilated food, retained bile, or any of those causes which produce that impure condition of the blood peculiar to the gouty.

That the urate of soda is the probable morbific matter may be gathered from the following facts-First, that the disease is to a great extent hereditary, occurring in families in whom the lithic acid diathesis is very strongly marked; secondly, the occurrence of an attack is not unfrequently preceded by circumstances which have led to a more rapid metamorphosis of tissue than ordinary, and the application of the exciting cause, cold and moisture, at this time, by checking cutaneous action, impedes that perfect conversion of the effete albuminous elements into urea; they are thus only partially oxidized into uric acid, which is generated in large quantities; thirdly, the simultaneous cessation of excessive deposits of urates, and the approach of

T

convalescence.

But rheumatism is not a disease of the blood alone, for we find that the urates may be largely deposited in the urine without the agonizing pain and the severe constitutional circumstances that attend rheumatism. We see this every day. A man has a severe cold, a good deal of febrile disturbance, heat of skin, and large depositions of urates of soda and ammonia; he may have the febrile excitement and no pain; in other words, febrile excitement depending on the application of the same cause and the generation of the same morbific matter in a less degree, but no rheumatism; clearly showing that rheumatism is not simply a blood disease. It is essential to the peculiar symptoms of rheumatism, that the circulation through the particular structures which become the nidus of the morbific matter should have been weakened and impaired by the depressing influence of cold. The vox populi, which attributes rheumatism to damp sheets, damp clothes, &c., recognises, quite as strongly as professional observation the fact that moisture as well as cold is essential to the generation of the disease. Cold, per se, acts primarily, and when not excessive, as a tonic and astringent; and its application, when in a state of health, is followed by that exhilarating reaction which we describe as a com

fortable glow. When the application of cold is more intense or more prolonged, it acts as a direct sedative; but cold air, if dry, although much more intense in degree, does not appear so favourable to the induction of rheumatism as a very much higher temperature when combined with moisture. The reason is, that water is a much better and more rapid conductor of heat than air; a given amount of cold will therefore, when combined with moisture, abstract more heat, and reduce the vitality of a part more rapidly than a much greater degree of cold uncombined with moisture. We find that the army medical statistics confirm these views, and that rheumatism is in Canada, where the air is very cold but very dry, a disease of much less frequent occurrence than at the Cape of Good Hope, where the geranium and myrtle are outdoor plants. It will naturally be asked, if cold and moisture are the exciting causes of the disease, how is it that of a number of persons exposed to the same exciting cause, only a fractional portion shall suffer from rheumatism? The answer is, simply because the predisposition exists in only a limited number; that predisposition is dependent on the existence in the circulation at the time of the application of the exciting cause of a larger quantity than common