Page 394. Forbes. chest, or back of the neck; a remedy which may always be unhesitatingly employed. In the treatment of the organic affections of the heart, it is always essential to adopt all those measures which will prevent the circulation being accelerated; and such means are more especially applicable in those cases where there is a morbid change of the valves. The processes of incretion and of excretion should be carefully regulated by due attention to diet, and the judicious use of purgatives. Locomotion should be guarded against, especially any immoderate muscular exertion; and all mental excitement is equally inadmissible; for, in the more aggravated form of valvular disease, death has in many instances immediately followed a violent muscular effort or mental emotion. By employing these different remedial agents, and judiciously adapting them to each case, it is surprising how long the lives of those suffering from diseased valves have in many instances been prolonged; and therefore, because there are many diseases of the heart which cannot be cured, we should not the less value those means by which they may be alleviated. "There is no disease, however hopeless, that does not admit of some mitigation, if not suspension, when managed according to the dictates of experience and sound pathology." CHAPTER XXXI. MORBID CHANGES OF THE MUSCLES OF THE HEART. Morbid changes of the muscles of the heart; peculiarities in the structure, functions, and diseases of the heart's muscles; the morbid changes of the muscular tissue enumerated; augmentation of the muscles; objections to the terms that have been employed to designate this condition; the diseases of the heart which cause an increase in the muscles; symptoms arising from this state of the heart's muscles; diminution of the muscular tissue; softening of the muscular tissue. BEFORE entering upon the investigation of the diseases of the muscles of the heart, we are first led to consider the nature of the functions which these muscles are destined to perform, and also endeavour to reveal peculiarities in their organization by which they are enabled to execute an office in some respects unlike that of other muscles. And when we reflect, that of all the vital organs the heart is perhaps the only one the functions of which cannot permit even a momentary interruption in its movements compatible with life, we may expect to find that there are peculiarities in the structure and also in the pathological conditions of its muscles,-peculiarities some of which have not yet been satisfactorily explained by the most diligent inquirers. The muscular fibres of the heart exhibit the characters both Peculiarities in the struc ture of the cles. of voluntary and involuntary muscles, some of them being plain and others striped. The small quantity of cellular tissue inter- heart's musposed between the fibres, their deep red colour, the proportionably larger size of their arteries when compared to those of other muscles, are all striking peculiarities in their anatomical structure.* In their functions, the heart's muscles are remarkable not only for their unceasing action during the whole span of life, but for "Even after death," observes Hunter, "we seldom see a dead body that is not stiff, but we very often find the heart large and flabby." Page 394. Forbes. chest, or back of the neck; a re In the treatment of the organic By employing these differen which that ncrease and a diminution in the res, an alteration in their consistence usion of blood, and the formation of e interstitial cellular tissue. Although ly met with in the muscular system, hæmatoid, and melanoid tubercles, are of the heart; some being formed in the in the fibrous lamina, both of the pericarndocardium. Deposits of bone and cysts us matter are not unfrequently found in the of the heart, and these usually in gouty e muscles of the heart, like other portions of stem, are also converted into fat, and into a ng spermaceti. ase of the Muscular Tissue of the Heart. the muscular hese changes, the most frequent is a preternatural Increase of 1 the number of the muscular fibres, or an enlargement fibres. rieties of the heart. ae voluntary muscles increase in size in proportion to the cy of using them, in like manner as they diminish when are seldom brought into action; but the same change is not with in the involuntary muscles, unless when the organs to ch they belong are diseased. This probably arises from the cumstance that when an organ into the composition of which here is a muscular structure, becomes diseased, as the urethra and alimentary canal, more powerful muscular contractions being required to propel the contents of the bladder and intestine, the number of their muscular fibres are increased. This change takes place in the muscular tissue of the heart when an increased vigour of its parietes is necessary in order to overcome an hindrance to the free passage of the blood through its cavities. An increase of the muscular tissue in such cases seems therefore to be a process of the economy-of the vis conservatrix-by which certain organs, when they have become changed in structure, are yet enabled to perform more or less perfectly their respective functions. Bichat. their rythmic contractions not being interrupted, even after the cardiac nerves have been divided, or the blood evacuated from the heart's cavities,- -a phenomena which continues in some races of beings after the heart has been for some hours removed from the body. It may therefore be truly said that "the motion of the heart appears to be innate, coming neither from the brain nor the blood." These peculiarities in the structure and functions of the muscles of the central organ of the circulation cannot fail to have a decided influence in the character of its diseases, and must surely be sufficient to point out how the heart's disorders will not be like those of any other organ. Thus we find that its "Anatomie muscles are never paralysed either in hæmophlegia or in paraPathologie." phlegia; and Bichàt was of an opinion that as only the muscles of locomotion are liable to convulsions, probably the heart is never affected with convulsive movements. I have already mentioned that the heart's muscles, as well as those of all the other organs of organic life, appear to be exempt from rheumatism, as an See Page 526. attack of that affection could not fail instantly to prove fatal. It may, indeed, be observed that throughout the whole animal creation means are provided to protect the different organs from diseases as well as from injuries, and these means are multiplied in proportion to the importance of their functions. Some are defended from atmospheric agencies by an external covering, or integument; some by osseous parietes; some by bony canals; and some are in pairs, so that if one be injured, the other is sufficient to perform the function. From whence it appears legitimate to infer that the heart of all the vital organs will be possessed of an organization, not only to protect it from injury and to secure the uninterrupted circulation of the blood, but that it shall be endowed with a structure to render it exempt from some maladies that are met with in other organs. Morbid changes of the muscular tissue. But whilst the heart is not liable to some of those diseases, an attack of which would immediately interrupt the circulation of the blood, its muscular tissue is, from the peculiarity of its structure and functions, more subject to certain ailments than perhaps any of the other muscles of organic life. The more remarkable changes in the muscular tissue of the |