The Humoral pathology, or that doctrine of the nature of disease which ascribed all ailments to excess, deficiency, or ill "concoction" of some one of the four humors (yellow and black bile, blood, and phlegm), had not yet lost its hold on men's convictions, or at least not further than to make them look upon exposure to cold and errors of diet as amply explanatory of all diseases not plainly infectious. The medical writers who were most revered were those who busied themselves with nosology; that is to say, the naming and classifying of diseases. Wonderful were the onomatological feats performed by some of these men, and most diverse and grotesque were the data on which they founded their classifications. To label a disease was high art; to cure it was something that Providence might or might not allow. In the treatment of "sthenic" acute diseases (meaning those accompanied by excitement and high fever), blood-letting, mercury given to the point of salivation, antimony, and opium, together with starvation (all included under the euphemism of "lowering measures"), were the means universally resorted to and reputed "sheet anchors." Some advance had been made from the times when disease had been looked upon as an entity to be exorcised, but it was still so far regarded as a material thing that it was to be starved out. But the century was not out of its second decade when signs of an awakening from this lethargy began to show themselves. The first steps, naturally, were along preparatory lines, and for those we are largely indebted to the physicists, the chemists, and the botanists. Gross anatomy became better known, owing for the most part to more enlightened legislation on the subject of the dissection of the human body; minute anatomy (histology) sprang into existence as the result of improvements of the compound microscope. Physiology took on something of the experimental; and medication was rendered far less gross and repulsive by the isolation of the active principles of medicinal plants. But it was long after all this that the telling strides were taken. Up to within the memory of many men who are now living, "peritonitis" tortured its victims to death, said "peritonitis" being often interpreted as a manifestation of rheumatism, for example, and no well-directed interposition was attempted against it, whereas we now know perfectly well that the vast majority of cases of peritonitis are due to local septic poisoning and for the most part quite readily remediable by the removal (with a minimum of danger) of the organ from which such poisoning arises--almost always the vermiform appendix. "Appendicitis," of which we hear so much nowadays, is no new disease; it is simply the "peritonitis" that killed so many people in former times. But while no well-informed person would now maintain that this disease was a new one, there are many, and those, too, among the best instructed, who find it