Erasmus Darwin

“ Now if any branch of the venous system loses its power of absorption, the part swells, and at length bursts and discharges the blood, which the capillaries or other glands circulate through them.
It sometimes happens that the large external veins of the legs burst, and effuse their blood; but this occurs most frequently in the veins of the intestines, as the vena portarum is liable to suffer from a schirrus of the liver opposing the progression of the blood, which is absorbed from the intestines. ”

“ It is possible, that when the motion of the lymphatic becomes retrograde in some diseases, that blood may obtain a passage into it, where it anastomoses with the vein, and thus be poured into the intestines. ”

“ Is not that hereditary consumption, which occurs chiefly in dark-eyed people about the age of twenty, and commences with slight pulmonary hæmorrhages without fever, a disease of this kind?—These hæmorrhages frequently begin during sleep, when the irritability of the lungs is not sufficient in these patients to carry on the circulation without the assistance of volition; for in our waking hours, the motions of the lungs are in part voluntary, especially if any difficulty of breathing renders the efforts of volition necessary. ”