They influence the intellectual functions, _i.e._ the mind, and the physical ties by which mind is connected with matter. These physical ties are,--the functions of volition and sensation, by which the mind is connected with the body, moving it or feeling it; and the five senses, by which the mind, through the body, is connected with external things. These intellectual properties, the centre of which is the brain, are more or less affected by Narcotic medicines. The first action of the latter is, to exalt these functions, just as they first exalt nervous force in general. The degree of this exaltation varies, as in the former case. Inebriants stimulate the mind to a considerable degree; Soporifics less; and Deliriants possess least of this primary exciting power. But it is in their secondary action on the mind that we find the most characteristic difference between them. On referring to the arrangement, it will be seen that I have divided Narcotics into the three orders to which I have already referred by name, and which are thus designated in Latin: NARCOTICA. Ord. 1. Inebriantia. Ord. 2. Somnifera. Ord. 3. Deliriantia. These Orders are named from the secondary action of these different Narcotics on the intellectual functions. In the production of inebriation these functions are impaired and deranged; in sleep they are lulled or extinguished for a time; and in delirium they are excited and led astray. The several actions of these orders will be more minutely described presently, and the individual medicines of which they are composed will be shown to agree with the general definition of Narcotics. Dr. A. Billing considers that Stimulants call forth nervous force, and Sedatives depress it; and that Narcotics do neither the one nor the other, but merely impede its communication. I do not consider this distinction to be quite correct. Narcotics exert in the first place a stimulant, and in the second place a sedative action; but these actions have no relation in degree, for one of them always exceeds the other, as we have just seen. Thus in the whole effect, either the stimulation must exceed the depression, or the depression must be greater than the stimulation. So that in one way or the other the quality of nervous influence must be altered. The medicines of the first order of Narcotics resemble Stimulants so far as this, that they tend altogether to increase the amount of nervous force. Perhaps Tobacco and Lobelia are exceptions to this. The medicines of the third order, and some of those in the second, tend on the whole to diminish the quantity of nervous force, and are thus akin to Sedatives. A correct understanding of the differences in action which exist between the groups of Neurotic medicines is, I think, very essential to a right application of these remedies in the treatment of disease. ORD. I. INEBRIANTIA. (Alcohol; Wine; Ethers; Chloroform; Camphor; Indian Hemp; Tobacco; Lobelia.)