The vital properties of the glands are never simultaneously excited in all. When one is in action, the others are in remission. We might say, that there is but a determinate quantity of life for all, and that one cannot live more without the others living less. To this law is the digestive order accommodated. In the first period the salivary glands furnish at first a great quantity of fluid; in the second, the parietes of the stomach; in the third, in which the chyme passes into the small intestines, the liver and the pancreas are principally in action; in the fourth, it is the mucous glands of the great intestines which especially act; and finally the kidneys enter into a particular action in order to evacuate the residue of the fluids. All the glands cannot act at the same time; it is as in the external motions in which certain muscles always rest whilst the others contract. The most improper time for coition is that of digestion, because we then make the mucous, hepatic, pancreatic secretions, &c. coincide with that of the testicles. In diseases one gland increases its secretion only at the expense of the others. Observation proves this every day. We might, as I have said, make use of this remark, by producing in various glandular and other affections, artificial catarrhs, a disease which we can always produce on the mucous surfaces by the introduction of a foreign body. I have for some time past made much use of ammonia respired by the nose. Pinel prescribes it before the paroxysms of epilepsy. There are an infinite number of other cases in which it is very efficacious, as in some kinds of cephalalgia, in ataxic fevers, in certain apoplexies, in various comatose affections, &c. A blister does not act till the expiration of some time; it requires four, five, six hours even for it to produce an irritation. Who does not know that oftentimes in diseases in which the forces are much prostrated, it has no action on the cutaneous system? On the contrary, the excitement of the pituitary membrane by ammonia is always sudden on the one hand and always efficacious on the other. Its effect, it is true, is only instantaneous, but this is precisely its advantage; for in many cases a blister is only useful the moment it irritates the skin; hence the use of drying it immediately and reapplying it. The employment of ammonia or of any other strong stimulant upon the pituitary membrane, can be repeated every quarter of an hour, every five or six minutes or even every minute. If habit renders the patient less sensible to its excitement, we can replace it by another irritating substance, whereas we cannot thus change the cutaneous excitement by a blister. What I have said of the pituitary surface is applicable to those of the rectum, the urethra and stomach, on which we can in many cases apply in diseases excitements in a more advantageous manner than is done upon the skin by means of blisters.