Now, the pathological changes described by numerous observers, such as parenchymatous and interstitial changes in the brain, destruction of the anterior grey matter, and, finally, the degenerative changes in the muscle groups, the macroscopical and microscopical atrophy of the muscle bundles with the fibrillation and other changes, are none of them opposed to the view that hæmorrhage and exudation are the earliest and initial change; in fact, in experimental animals minute hæmorrhages could always be traced in the earliest stages of poisoning, frequently before definite symptoms appeared. Confirmation of this theory is seen in the work of Glibert[40], and the drawings he gives showing fibrous changes in the lungs, hyperplasia, congestion, and emphysema, cirrhotic conditions of the liver, and, as he describes it, blood-stasis caused by elongation and dilatation of the capillaries, are all of them highly confirmatory of the hæmorrhage theory. Further confirmation is also afforded by the observations on the action of lead salts upon the blood itself. From the earliest days lead has been used as a styptic, and its empirical use has been shown by later observation to be due to its power of readily coagulating albumin and peptone. Further, in chronic lead poisoning there is a marked increase in the coagulation time of the blood. Glibert, in the work already referred to, points out the increased ductility of the red blood-cells in lead poisoning. Quite apart from this, there is no doubt that definite alterations in the red blood-cells occur; a species of icterus is common in lead poisoning, the anæmia of lead poisoning is of a destructive type, increased urobilin may occur in the urine, and in some instances hæmatoporphyrin is present in considerable quantities. The bone-marrow in cases of lead poisoning undergoes distinct inflammatory change, and may possibly be the cause of some of the curious aching arthralgias often noted as a clinical symptom. All the pathological evidence that can be adduced points unmistakably to the blood as suffering the initial stress in lead poisoning, and it is therefore by no means surprising that the blood vessels should be the next in order to undergo degenerative changes. It is probably this degenerative change, particularly associated with the increased coagulability, alteration in viscosity, the destruction of the blood-cells themselves, and the permeation of the vessel walls by definite, if exceedingly minute, quantities of lead salts, that determines the yielding of the smaller and generally the weaker bloodvessels. In the histological examination of the experimental animals there was considerable evidence that the venules, rather than the arterioles, are the first to yield.