All the agents of which we have spoken, with the exception of tobacco, whose action from the first is decidedly sedative, operate partly by stimulating the frame. They cause the heart to throb more vigorously, and the blood to circulate freer, while, at the same time, they exert a peculiar action upon the nervous system. The nature of this action, it is probable, will never be satisfactorily explained. If mere stimulation were all that was wanted, drunkenness ought to be present in many cases where it is never met with. It, or more properly speaking, its symptoms, ought to exist in inflammatory fever, and after violent exercise, such as running or hard walking. Inebriating agents, therefore, with few exceptions, have a twofold action. They both act by increasing the circulation, and by influencing the nerves; and the latter operation, there can be no doubt, is the more important of the two. Having stated this general fact, it will be better to consider the cause of each individual symptom in detail. I. _Vertigo._—This is partly produced by the ocular delusions under which the drunkard labours, but it is principally owing to other causes; as it is actually greater when the eyes are shut than when they are open—these causes, by the exclusion of light, being unaccountably increased. Vertigo, from intoxication, is far less liable to produce sickness and vomiting than from any other cause; and when it does produce them, it is to a very inconsiderable degree. These symptoms, in ninety-nine cases out of a hundred, arise from the disordered state of the stomach, and not, as we have elsewhere mentioned, from the accompanying giddiness. There are, indeed, a certain class of subjects who vomit and become pale, as soon as vertigo comes over them, but such are few in number compared with those whose stomachs are unaffected by this sensation. In swinging, smoking, sailing at sea, on turning rapidly round, sickness and vomiting are apt to occur; and there seems no doubt that they proceed in a great measure from the vertigo brought on by these actions. The giddiness of drunkenness, therefore, as it very rarely sickens, must be presumed to have some characters peculiar to itself. In this, as well as in some other affections, it seems to be the consequence of a close sympathy between the brain and nerves of the stomach; and whatever affects the latter organ, or any other viscus strongly sympathizing with it, may bring it on equally with inebriating agents: calculi in the uterus or biliary ducts are illustrations of this fact. In intoxication, the giddiness is more strongly marked, because the powers both of body and mind are temporarily impaired, and the sensorium so disordered as to be unable to regulate the conduct.