Dr. J. Burdon Sanderson on the process of fever.

  • Burdon-Sanderson, John Scott, 1828-1905.
Date:
[1875]
Catalogue details

Licence: Public Domain Mark

Credit: Dr. J. Burdon Sanderson on the process of fever. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    The purpose of the inquiry being to compare the exchange of material Appi^°-1 and of heat in the febrile state with those of health, it was necessary On the Process before proceeding further, to bring the animals to be employed (dogs) ])r. Burdon into a condition of nutritive equilibrium. With this view each animal was Sanderson, placed for a sufficient time preceding the period of observation, on a diet of carefully-selected horseflesh, which was increased or diminished until the body-weight and daily discharge of nitrogen in urea, and the “ insensible loss became severally constant. After it had been kept on this regulated diet for some days, food was withdrawn for a period of 48 hours, during which the normal discharge of carbonic acid, water, urea, and of heat were measured. The diet was then continued as before until nitrogen equilibrium was once more established. This having been accomplished, fever was induced by the subcutaneous injection of perfectly fresh pus, and determinations of the same kind as had been previously made, were repeated under exactly similar conditions as regards nutrition during a second period of 48 hours. The febrile condition induced was well characterized. The temperature (as measured in the rectum) began to rise in from one to two hours after the injection of the purulent liquid, the pyrexia continuing for about two days. During the accession there were rigors, and the skin felt hot to the finger ; subsequently the animals were listless and anorexic, and drank water with avidity whenever it was supplied to them. Each experiment therefore comprised two 48 hours’ periods of observation, separated from each other by an interval of several days, during which periods the production of heat, the changes of bodily weight, the daily quantities of urine and urea excreted, and the respiratory and cutaneous discharges of carbonic acid and water were determined. The carbonic acid determinations, and the calorimetrical observations, however, related only to limited periods of measurement, each lasting an hour, repeated once or twice during the day. The “ insensible loss’’was computed for each period by adding the weight of ingesta to the total loss of weight in twenty-four hours, and deducting that of the excreta. As thus reckoned the | result for any period of observation would, if the weight of oxygen absorbed I were equal to that discharged in the form of carbonic acid, express the discharge of water and carbon from lungs and skin. As however the weight of oxygen taken in in respiration is always in excess of the weight given off, it must be borne in mind that this excess, which is a variable one, is comprised in the so-called “insensible loss.” Putting this statement into the equation form :— Insensible loss = H20 discharge + C02 discharge— O absorption. The collection of the urine in animals is a matter of great difficulty. As regards the dog, the only method that was found to ^.successful is that of training the animal to empty its bladder at stated intervals. Unfortunately | this cannot be done without much trouble. For the continuous collection of the ' products of respiration and cutaneous exhalation, the animal was placed in a | ventilated chamber, which was so arranged as to answer the purpose of a j calorimeter. Its construction mil be described in the next section. In some instances the carbonic acid was determined volumetrically by Pettenkofer’s method, in others by the balance. The water-vapour in the air discharged from the chamber was determined by weight, the apparatus for the purpose 1 being of course interposed between the exit tube and that for the absorption of r carbonic acid, so that the air reached the latter in the dry state. In most of | the experiments the air as introduced into the chamber was completely I n saturated, so that its temperature being known, the per-centage per volume of j' aqueous vapour it contained could be calculated. This being the case, the j difference between this per-centage and that of the outflowing air gave the | quantity of water exhaled by the animal. It was recognised, however, by IT 1A- Senator that this determination was not exact, for of the out-going water- vapour much must have been lost by condensation on the wall of the chamber. I Considering that in fever the natural ingestion of food is reduced to a minimum] J.*it is obvious that any comparison made between an animal normally fed, and a » O