till it becomes distended or contracts. All the bile secreted can thus be removed by a fistular opening in the gall-bladder without tying the gall-duct, but when the fistula is closed it passes into the intestine. When all the bile is thus removed the amount secreted becomes much diminished, but again rises when the bile is re-injected into the intestine, stomach, veins, or under the skin. Ox-gall or the soda salts of bile-acids have a similar action. When much bile is injected into the intestine bile pigments are found in the urine. As former experimenters have withdrawn all the bile and not re-injected it into the intestine, their estimates of the amount secreted are too small, and Schiff reckons it at 1.3 to 3.2 gr. in an hour for every kilogramme of body weight. When the portal vein is slowly obliterated by a ring of thread put round it and gradually pulled upon, bile-colouring matter appears in the urine, but disappears in 3 weeks. When the salts of bile acids are injected into the blood, bile pigment is found in the urine, if the fistula be closed, but not if it be opened, shewing that the pigment in the urine is due to absorption of bile from the intestine. These changes in the amount of bile secreted are observed in sick as well as healthy dogs, and are not due to slowing of the pulse from the bile absorbed, as digitaline has no such effect.

FORMATION OF UREA IN THE LIVER.-E. Cyon (Centralblatt f. Med. Wiss. 1870, p. 580) estimated the amount of urea in blood drawn from the carotid of a dog and then passed one or more times, according to Ludwig's method, through the excised liver of the same animal. After passing through the liver the amount of urea it contained was increased; in one instance where the same blood was passed through the liver four times, it was more than double that contained in blood from the carotid, showing that a considerable amount is formed in the liver.

Temperature.

CAUSE OF FEVER.-Naunyn (Reichert and du Bois Reymond's Arch. 1870, 159) found that when heat was retained within the body of a dog by placing it in a warm atmosphere saturated with moisture the temperature in the rectum rose 71°, and the urea rose in the next 24 hours from 6.7 to 9.76 grammes. This seemed to render it probable that retention of heat in the body was the cause of fever. Farther experiments however proved that this was not the case. He injected putrid matter into the veins of a dog and found that the excretion of urea was increased during the next hour or two, while the fever thus produced was still latent and before the temperature of the animal was increased. If fever had been dependent on retention of heat there should have been no increase of urea till the temperature of the body rose.

Senator (Virch. Arch. L. 354) thinks that the production of heat in the body is not increased by cooling the surface, and that no conclusions on this point can be drawn from observations made in the axilla alone, as variations in its temperature and that of the rectum do not run parallel. On cooling the naked body of a strong young man

30

he found that the temperature in the axilla rose 3th to 1o C., while that in the rectum sank slightly. After several minutes that in the axilla began to sink and sank constantly even under the normal till the experiment was stopped. The slight diminution in that of the rectum was succeeded by a slight rise, and this again by a constant fall. He thinks that the contraction of the vessels of the skin produces a slight accumulation of heat at the periphery shown by the rise in the axilla, and that this passes gradually inwards till it produces the rise in the rectum. The body may be cooled so that the temperature rises in one axilla while it falls in the other. From these experiments he concludes that cold baths in fever diminish the temperature without causing any increased production of heat.

EFFECTS OF ABSTRACTION OF HEAT.-Horwath (Wien Med. Wochensch. 1870, No. 32) found that on cooling rabbits with snow and ice, the frequency of the pulse was diminished and the power of the vagus over the pulse and blood pressure destroyed at 23°C. The intestines and bladder were motionless and did not contract on electrical irritation. Peristaltic contractions could be induced in the former by dropping warm water upon them, but these disappeared on the reapplication of cold. Compression of the carotid had no effect on the blood-pressure and produced no convulsions, but inflation of the lungs diminished the pressure and altered the pulse-rate. These effects disappeared when the temperature of the animal was again raised.

DIMINUTION OF TEMPERATURE BY PAIN.-Horwath (Centralblatt, 1870, p. 546) had found that the temperature in the rectum of rabbits tied down to a board constantly sank sometimes 2o C., and this was not due to simple want of movement as it did not sink more than C. when they were simply put into a narrow box in which they could not move. He therefore imagined that it might be due to the pain caused by the cords and on pinching a little piece of skin 2 or 3 centimeters in diameter he found a similar sinking of the temperature.

DIMINUTION OF TEMPERATURE BY GAS IN THE INTESTINES.-Simons (Inaug. Diss. Bonn. 1870. Brit. Med. Chir. Rev. 223. Jan. 1870). Carbonic acid, carbonic oxide, hydrogen or air when injected into the intestines or subcutaneously cause an immediate fall of temperature, attaining its maximum in 2-6 hours and then gradually rising. The maximum fall is 10° C. Pulse and respiration were also somewhat slowed but they were not affected so much as the temperature.

INFLUENCE OF FOOD AND DIGESTION ON TEMPERATURE. -Vintschgau and Dietl have found (Wien. Acad. Sitz. Ber. Math. naturwis.Cl. Bd. LX. Abth. II. p. 69) that warm food introduced into the stomach of a dog with a gastric fistula raised the temperature of the body, as observed by a thermometer in the rectum, while cold food depressed it. When the food was warmed to nearly the same temperature as the body, the temperature fell in the course of two or three hours about both of a degree, and then rose 1° to 1° C. above its original one. The temperature of the rectum sank and rose in a parallel manner.

VOL. V.

27

NORMAL AND PATHOLOGICAL TEMPERATURE. -Jacobson (Virchow's Archiv, LI. 275) in conjunction with Bernhardt and Leyden has carried on his researches on this subject. Some results have already been detailed in a former number of this Journal (Second Series, No. IV. May, 1869). With reference to the question whether fever heat is due to retention of heat, i. e. an equalisation of temperature between warmer and cooler organs within the body, or to absolute increase of temperature, Jacobson and Leyden found that in fever resulting from injection of pus, or croton oil inflammations, the temperature increases both in the liver and in the rectum, which could not be the case if there were merely an equalisation of temperature. The authors, however, do not think that the source of the increased heat is the local inflammatory processes (as held by J. Simon and and Billroth), for they found, that though the temperature of the inflamed limb is higher than that of the other, yet it is always lower than that of the abdomen, rectum or vagina. They likewise find that there is no difference in temperature between a pleura inflamed by injection of ammonia or acetic acid and the pleura of the other side.

EFFECTS OF CEREBRAL LESIONS ON THE TEMPERATURE OF THE BODY.-Bruck and Günther (Pflüger's Archiv, III. 578) find that an elevation of temperature is more surely produced when puncture is made in the anterior part of the pons or posterior part of the medulla than after separation of the medulla from the pons. Hence they conclude that the elevation of temperature is to be considered as the effect of irritation, rather than paralysis of an inhibitory centre as Tscheschichin supposes.

INFLUENCE OF THE NERVOUS SYSTEM ON THE TEMPERATURE AND CIRCULATION.-R. Heidenhain (Pflüger's Archiv, III. 504) was led to researches on this subject from experiments made with a view to determine the temperature of the brain in different conditions. He found that the brain always possesses a higher temperature than arterial blood, and that this difference is markedly increased on stimulation of sensory nerves. There is a fall of temperature in the arterial blood, but this does not take place if the spinal cord is severed from the medulla oblongata. Along with the fall in temperature there is increase of the blood-pressure. He believes that the fall of temperature is not due to mere disturbance of the circulation effected through the medulla. He finds (in opposition to Dogiel and Kowalesky) that with the rise in arterial pressure the pressure in the veins is also increased and also the velocity of the blood-current. Hence he concludes that as the fall of temperature is not due to slowing of the blood current through the influence of the sensory nerves on the medulla, it must be due to increased radiation from the surface. finds a confirmation of this view in the fact that, when the body is immersed in a cold bath, the internal temperature rapidly sinks on irritation of sensory nerves, while the reverse is the case in a warm bath where no radiation from the surface is allowed.

He

SEPTICEMIA.-Albert and Stricker (Medic. Jahrbüch der K. K. Gesellsch. d. Aertzte, 1871, Heft 1) find that the increased temperature produced by the injection of pus into the veins may be due to irritation produced by the local wound or embolism, and not to a specific poison. When a vein was simply tied the temperature rose during the operation, fell after it, and again rose in the third hour afterwards. When anything was injected, the temperature rose in the first hour and did so after a certain rhythm, the rise being at first regular, then quicker, and then again suddenly slow. Rigors occurred when the rise began or when it became quicker. Injection of per cent. Na Cl solution or spring water produced the same effect as diluted pus. Pure pus caused a quicker rise, but this also could be imitated by injecting water holding a number of starch granules in suspension. When the crural vein is connected by a canula with the crural artery, so that blood flows out of one into the other, a rise in temperature is also produced.

Injection of fresh defibrinated rabbit's blood into the peritoneum of a dog produced vomiting, purging, and laboured breathing, just as pus had been found by Weber to do when injected into the thorax. When an animal was bled, and the blood of a feverish animal transferred into it, its temperature fell and did not rise so quickly to the normal as when healthy blood was transferred.

INDEX TO VOLUME V.