2. But there are also the substances which the living body compounds or modifies for itself. It has been said that the organism is the receptacle and laboratory of poisons; in the state of emotion, the only one with which we are concerned at present, the function of this chemical process is manifested at every instant. We are always speaking of the weakening or the increase of the circulation of the blood; yet the emotional dispositions or modifications are connected, not only with variations of quantity, but also with those of _quality_ in the blood (anæmia, aglobulia, malarial poisoning, etc.). The popular expression regarding the emotions which “curdle the blood” is not so ridiculous as it might seem. Anger, fear, fatigue are often accompanied by changes in the intimate constitution of the sanguinary fluid. We may incidentally note the ascertained relations between certain cardiac affections and affective dispositions: in aortic affections, anæmia, excitement, irritability; in cases of mitral insufficiency, congestion, and a taciturn and melancholy humour. We shall elsewhere have occasion to enumerate the facts which show the correlation of certain emotions with toxic changes in the saliva and the lacteal secretion. Perspiration may, in certain affective states, be coloured red, yellow, green, or blue, not to mention the varieties of odour, which are assuredly of chemical origin. Even apart from mental disease, the urinary secretion could furnish a long list of chemical changes (azoturia, oxaluria, phosphaturia) coinciding with variations of the affective order, such as apprehension, melancholy, irritability. In gouty and rheumatic patients, the modifications of temper, depending much more on general nutrition than on active suffering, have often been pointed out. We know the relations between the secretion of the gastric juice and pleasurable or painful states; dyspeptics have a well-established reputation for being neither cheerful nor comfortable to live with. Beaumont ascertained, in the case of his famous Canadian, that under the influence of anger or other very strong emotions, the lining of the stomach was irritated, became red, dry, and very sensitive, and an attack of indigestion was the result. The rutting time (that of sexual excitement) is, in many animals, accompanied by deep-seated chemical changes, showing themselves externally by modifications of colour and odour, and, internally, not limited to the sexual organs, but extending to the whole of the body. It is known that the flesh of game is uneatable during this period, and that many fish, at spawning-time, become poisonous. It should not be forgotten that, during the same period, the animal becomes vicious, violent, aggressive, and dangerous. It would be easy to develop this point further, even as regards man (puberty, gestation, lactation, menstruation).