There are two principal causes which govern the rapidity or tardiness of appearance of substances in the secretions; the first of these is the tolerance of the system for the substance; the second is the quantity of the substance present at one time in the economy. The tolerance is in relation to the nature of the substance. It is probable also that the degree of solubility or ina Prof. R. T. Edes. c Fehling. e Koebner. b Lewin.

b Prof. Adolph Gubler. d Dugardin Beaumetz. a Mialhe.

solubility or insolubility of a substance has marked influence on the prolongation of its sojourn. a

Bromide of potassium may be eliminated in 10 or 15 minutes. Chlorate of potash is eliminated more slowly than the bromide, but not. always. It is reported by different authorities that the elimination of the bromide of potassium varies; thus Amory recovered one-half of the amount ingested during the first and one-third during the second twenty-four hours, and Mr. Ware obtained a little more than one-half of the amount ingested in the urine of the succeeding thirty-two hours, while Dr. Bill was not able to get more than one-eighteenth of it during the first day. Dr. Bill has frequently found the bromide in the urine two weeks after the last dose had been exhibited; and Dr. Rabuteau has seen its presence persist under similar circumstances for a month.

It has been ascertained that six days sufficed for the. complete elimination of the iodide of potassium after its exhibition during fifty days. b On a single maximum dose, you will have half the iodide eliminated in the first three or four hours, the second half will require the following 24 hours. a

According to Briquet, quinine may generally be found in the urine half an hour after the administration of a large dose. Its removal, according to the researches of Binz, goes on slowly, for it is stated that in six experiments only a little more than two-thirds of the ingested quantity was excreted in the first 48 hours. Further, De Reuzi,yvon and Dielt have found it in urine six or seven days after the ingestion of the last dose. Welitschkowski found an elimination of 65 per cent. the first day and 25 per cent. the second day. Prior gives the second day as the usual final limit of elimination. c

Antipyrine is freely absorbed and as freely eliminated by the kidneys. e It appears in the urine from 25 to 30 minutes after its ingestion and continues for 36 hours, although most of it is eliminated in the first 12 hours. d

There is a peculiar retardation which follows the administration of digitalis, its period of elimination lasting from 10 to 15 days. It appears that digitalis cannot maintain its effects, unless it is held in reserve in the tissues. It is not then eliminated gradually, and completely during the period it penetrates. a

When mercury is administered repeatedly, elimination ceases before it is all discharged. Thus forty-eight hours after the cessation of a mercurial course when the urine of one of the investigation was free from the metal, the iodide of potassium was exhibited and the urine of the next 24 hours contained an abundance of mercury, which continued to be present in diminishing quantities for 72 hours. The chief channel of escape seems to be the kidneys; but it is very certain that in some cases the drug is freely excreted by the salivary glands, as well as by the intestines. It has been found in the faeces three months after the cessation of a mercurial course, indeed it may be eliminated more freely aprof. Adolph Gubler. cprof. H. C. Wood. em. Queveune.

bKramer. darmand.

and constantly by the intestines than by the kidneys. It is supposed that the elimination is completed in six months after the cessation of an ordinary mercurial course. e

Elimination of the Urates.

Urates themselves are colorless; but the amount of pigment they carry with them, varies with the different circumstances under which they are formed, hence the significance of their color. The paler the urate deposit the more urate of soda is present; the deeper colored, the larger the proportion of urate of ammonia. White deposits of urate of soda are associated with indigestion, deep urate deposits, with pyrexia, organic diseases, or the concentrated urine of venous fullness, as in cardiac failure. a The urea in renal diseases may even form a distinct crystalline powder on the skin, but it is most abundant about the mouth of the sweat gland. b

The urates may be increased or diminished by the introduction of different substances. All preparations of iodine will increase the elimination of uric acid. b Salicylic acid in gout will greatly increase the exhibition of uric acid, but both in health and in disease the urea is unaffected.

In nitrate of soda the quantity of urea is increased for the first few days following the administration of the drug; it then returns to and even falls below the normal quantity. c In jaborandi the chlorides were found in excess, the carbonates and phosphates in very minute amount, and the urea in more than five times its normal proportion, the amount eliminated in the sweating being estimated at from 10 to 15 grains. The saliva contains an abundance of salts and of ptyaline, as well as a small excess of urea. b Hardy and Ball state that in health ureaelimination from the kidneys is diminished by the drug, while Prof. Tyson and Dr. Bruen have found it increased both in health and in disease.

Chelius announced that during the administration of colchicum in gout the amount of uric acid eliminated is nearly double. On the other hand Prof. Stille states that Graves and Gardner affirm that the urates diminish under the use of colchicum. Dr. Hammond found that while squill and digitalis only increased the watery part of the urine,both the organic and inorganic solids were remarkably increased by colchicum.

Quinine is one of the remedies that produces a great decrease in the elimination of uric acid. d In man an ounce of glycerine daily, produced in the elimination of urea a decided diminution, which was not increased by increasing the dose of glycerine. Munk found that glycerine has no effect upon the elimination of urea or the general bodily nutrition. It is said that the solutions of the lithia salts have the power of dissolving uric acid and the urates.

aJ. Milner Fothergill. cdr. L. Lewin.

cSchuster.

bProf. H. C. Wood. dranke.

The Elimination of Medicines by the Mammary Glands.

To a limited extent a child may receive medical treatment from the milk containing the elimination of the medicine the nurse has taken. But it is a method of little reliability owing to the physiological changes in the secretions of the the glands. These are greatly influenced by circumstances - some of a physical nature - others mental. The mother may at one time take a large dose of opium with no effect on the child; at another, she may take a less quantity which may dangerously narcotize the child. What makes the difference? The secretions of the mammary glands possess a highly elective force, by which is maintained as much as possible, the purity of the milk. When this force is at fault, or for the time suspended, extraneous material is apt to be admitted. There are some drugs that have a tendency to be eliminated with the milk, as opium, iodine, hyoscyamus, salicylate of sodium, antimony, quinine, volatile oils and the purgative principles of rhubarb, senna, aloes, scammony, castor oil, sulphur, etc. The neutral salts as a rule pass into the milk and cause looseness of the bowels in the child. When the secretions of the glands are highly excited, as they are, soon after parturition, after a purgative, or after an active physical exertion or violent mental excitement greater care than visual is demanded in prescribing a drug that may have an elective tendency to the mammary glands.

Another cause inviting drugs to the mammary glands, is when the milk is poor and thin. When it is rich, with its proper equivalents of fat, albumen, and sugar (lactine and lactose) the elimination of drugs through the glands is less likely to occur, and when it does take place, the rich milk will render a protection through a subsequent action of the liver of the child.

Mental influences may greatly affect the secretions of the mammary glands. Violent fits of anger of the nurse may impart toxic properties to the milk, even as cases on record show to prove fatal to the child. In such cases, we have reason to believe, that the glands would relieve themselves of the poison in an hour or so under the elective force already referred to.