Sir Samuel Wilks was a British physician and gave an excellent account of infective endocarditis in a concise article published in 1870. His article was entiltled "Capillary embolism or arterial pyaemia."
He first discussed Kirkes paper indicating that the latter had mostly concentrated on large systemic emboli. Wilks in his work mostly focused on the systemic effect of the dispersion of these "fibrinous deposits" in the small vessels of organs. He then emphasized on the occurrence of "arterial Pyaemia" and its attendant constitutional symptoms of fever, rigors, and arthritic pain.
Wilks believed that these systemic manifestations of "blood poisoining" were more often the cause of death than the primary valvular lesions:
"A patient for example, is in the hospital for valvular disease of the heart arising, perhaps from rheumatism at some former period; whilst under observation he may have febrile attacks attended by articular pains, but these are regarded as touches of the primary complaint; and when after death the valves are seen covered with vegetations, and the spleen and kidneys full of softening fibrinous masses, these are in no wise regarded as having been instrumental to the fatal event, but as mere accidents of the disease. It must, however, have often, I believe, occurred to the observer that the derangement of the valvular apparatus was scarcely sufficient to cause death."
Wilks also postulated that the "fibrinous deposits may occur from changes in the blood itself."
"...In many cases the deposit may have occurred from a primary change in the blood itself, since often there is no proof of the existence of a primary endocarditis; in fact, there has been reason to believe that in some cases the deposit found on the valves of the heart has occurred simultaneously with the deposits in the solid viscera. It must be admitted that if, on postmortem examination, there be found associated with these deposits in the viscera some vegetations on the cardiac valves, it would be presumptuous to deny that an endocarditis might have been the origin of the whole train of subsequent events; yet, on the other hand, it would be a practical error not to be awake to the possible occurrence of arterial pyaemia, because there is no history of a primary cardiac affection."
He then continued:
"In these cases it is probable that the first symptoms which attract attention will be the constitutional ones, and that febrile symptoms and occasional rigors will suggest the existence of ague..After a short time it is possible that the liver and spleen may be felt enlarged, and still the obscurity remain. At a later period a bruit may be heard, which may be styled aortic or mitral, according to position. The febrile symptoms continue, and the patient, perhaps after a protracted illness, dies; the organs are found affected as described, and vegetations on the valves of the heart."
In his conclusion, Wilks summarized his findings and mentioned that the diagnosis of arterial pyaemia should be suspected in the presence of "obscure febrile conditions."
"I would say, therefore, that arterial pyaemia is a by no mean uncommon affection, and that it is seen frequently in chronic heart disease; but the symptoms are overshadowed by the more severe ones attendant on the valvular imperfection, or, if observed, regarded merely as rheumatic. Also, that it may be often met with where there is no history of a primary heart affection, although an endocarditis at the time of occurrence of the symptoms may exist. Also that it should be suspected in cases of obscure febrile conditions, especially if accompanied by rigors, and more especially where the liver and spleen have been found to be slowly increasing in size."