There are two organs whose especial function is the removal of deleterious substances from the blood: the kidneys for fluids or solutions; the lungs for gases and vapors. In the former, the blood loses large quantities of fluid, which by adr. Gregory.

the laws of diffusion, must carry with it appre ciable quantities of the substances in solution in the serum. In the latter, at least during respiration, large blood surfaces are in contact with the atmosphere, and since this atmosphere at best can contain but traces of the deleterious gaseous substances in the blood, and therefore under less tension than in the blood, they tend to constantly diffuse, under ordinary physical laws from the blood into the air in the lungs.a Exceptional circumstances may, however, occur in which these physical processes will be either hindered or facilitated. For example, diffusion will be prevented by chemical union of the foreign bodies with the ingredients of the blood, or accelerated by the chemical forces tending to displace them from the blood. As an illustration of the former condition, carbon monoxide may be mentioned, which from its chemical relation with the blood shows no tendency to diffuse into the air in the lungs, while, as an example of the second, carbon dioxide, though forming a chemical compound with the blood, is diffused with the greatest readiness; similar conditions exist in regard to eliminations of substances through the kidneys.b

As in the kidneys, so also in all the other emunctory organs, there is probably a tendency to the elimination of foreign substances from the blood, therefore drugs after absorption may appear in the saliva, in the mucus, the gastric, intestinal or pancreatic juices; or in bile, in the digestive apparatus; or in the sweat, milk, tears, or lymph juices. Of these secretions, the milk, sweat or saliva can serve to eliminate the poison entirely from the system; the others can remove it only temporarily from the blood to place it under circumstances where it again meets conditions favorable for reabsorption into the blood by the vascular or lymphatic vessels. The laws which govern this intermediate circulation of poisons, the normal results of tissue change, are almost entirely unknown.b

Volatile and gaseous substances are eliminated by the respiratory organs, on the one hand, on the other, by sweat glands. These glands, acting in conjunction with the organ of respiration give issue, not only to volatile substances, such as the fatty acids, but even to sulphuretted hydrogen, and carbonic acid. At the same time these glands take from the atmosphere the gases which compose it, and in particular, oxygen, which afterwards serves to keep up respiratory combustion. This phenomenon is not very marked, but it is notable. In this way are eliminated carbonic acid, sulphuretted hydrogen, phosphoretted hydrogen, and all compounds derived from it, most of the essential oils, as also the camphors properly so-called originating from the labiatae and compositae, alcohol, and a number of substances equally volatile, ether and many anaesthetic compounds and volatile alkaloids.

To excite cutaneous secretion, recommend volatile substances. When fatty acids are conadr. G. P. Hachenberg, on tho relation of Atmospheric Air to the Human Body, Western Lancet (Cin. O.), Vol. xv, No. 10.

bProf. L. Hermann.

tained in the aliment as in cheese, there will be excitation of the skin. This kind of aliment should then be prescribed when treating irritative cutaneous affections. You may excite lacteal secretion by the feculents, sugar, fatty bodies, by aromatics even. It is by the skin that substances of this order are eliminated, and milk itself owes a portion of its qualities to the aroma it presents.

The most astonishing feature of the gaseous exudation from the glandular system of the skin is its physiological individuality. Not only has each animal a peculiar odor of its own, but this applies also to each individual of the same kind. This is fully demonstrated throughout all animal life. By the sense of smell, the dog will hunt up his master in the greatest crowd - the blood hound will trail a fugitive with the same unerring instinct - an animal mother will recognize her own young in like manner; and among the bees, each colony if not each bee has its own distinctive effluvia.

There are what Gubler terms directive bodies, which sometimes seem to give their veto to the passage of a substance, and in other cases cause it to pass by a route which it never follows of itself. Thus, camphor prevents cantharides from passing by the kidneys; also iodine which combined with iron, compels the iron to pass by the salivary gland, although it never follows this route except under these particular conditions.

Mercury is eliminated by all the secretions, but especially by the urine. b It has been found in the blood, g in the saliva, d in the serum and pus of ulcers, e in the faeces, f in the seminal fluids, g in the milk of nursing women, h indeed, in every conceivable secretion and in every tissue.a It has even been found in the aborted foetuses of salivated women, b and in the urine of a baby whose nurse was taking calomel. g

When ammonia is administered internally it is by reason of its affinity for the pulmonary mucous membrane, by which it is in a great measure excreted, that it serves as a valuable stimulant to the lungs; it is also beneficially employed in restoring the action of the heart, when abruptly depressed and overpowered by some devitalizing agent. d

Saccharin is eliminated entirely by the kidneys. It may be asked if it will not act favoraably on pyelitis and pyelo nephritis. e Vesical catarrh with ammonical urine has been successfully treated with saccharin. f

Boracic Acid, the urine readily and rapidly eliminates, and as would be supposed, it is useful internally in cystitis. g

Chloride of potassium is eliminated by the salivary glands and those adjacent, and therefore is an effectual cure in a certain number of buccal affections. a agubler.

cBuchnerand Eld.

eFourcroy.

gMayencon.

aProf. H. C. Wood.

dMay.

fClemens.

bEdes. dgruelin. flalkowsky. hkluck.

bHeller of Vienna. em. C. Paul. ggaucher.

Emetine is eliminated through the digestive apparatus, and has the singular effect to be eliminated at the place of introduction, when administered by the stomach.