his sugar metabolism is concerned with the removal of his thyroid.

If we study other curves of thyroidectomized dogs we find the same condition prevailing, the rapid intake during the first hour in the normal dog and the slow, gradual intake and equally slow output following. The amount of blood sugar in the cretinized animal never reaching the amount in the normal animal, but the retention lasting over a much longer period.

Janney concludes, therefore, that cessation of the thyroid function results in hypoglycemia and delayed removal of sugar from the blood, may we expect, on the other hand, that a hyperthyroid condition will result in an exactly opposite condition? If this is so and if it can be proved to be a constant occurrence it is readily seen that we have a most useful method for determining our thyroid function. The blood sugar curves of exopthalmic goitre before and after treatment (Fig. 3) show graphically the sudden, sharp rise and sharp fall that is indicative of the sugar intolerance of this disease.

How useful the application of these facts has proved in our work at the San Francisco Hospital for Tuberculosis I shall show later. Another means of identifying a hyperactivity of the thyroid is that a constant manifestation of thyrotoxicosis is a rise in the general heat production.

Means and Aub, Jour. A. M. A., July, 1917, have made a large number of observations on the metabolism of goitre patients under different modes of treatment and their results are most interesting.

The patient's heat production is measured by calculation from his gas exchange, which is determined by Benedict's respiration apparatus. By indirect calorimetry the number of calories produced can be calculated, pro

been done upon the thyroid so that we may, if possible, formulate a method of thyroid function examination that will enable us to clear our hospitals of purely thyroid cases and treat more intelligently those unfortunate patients who are suffering at the same time from tuberculosis and thyroid poisoning.

We know that the thyroid exerts a profound influence on sugar metabolism. We are accustomed to find glycosuria in exopthalmic goitre. We are accustomed to find glycosuria after injections of adrenalin for asthma, and we know that this substance, adrenalin, increases the thyroid function.

Janney-Arch. Int. Med., August, 1918, has shown in a most beautifully graphic manner the effect of thyroid activity on the amount of sugar in the blood.

Previous experiments in thyroidectomized animals have been more or less contradictory. This may have been due to the difficulty of removing the thyroid without injury to the parathyroids, or it may have resulted from the unreliability of the tests used. It is only lately that tests for sugar in the blood have been sufficiently accurate to give constant results.

Janney overcame these sources of error by utilizing a careful surgical technique and the employment of more accurate methods of blood sugar analysis. Also by the utilization of a sufficient number of dogs to render the results dependable.

Normal blood sugar curve in dogs after ingestion of the weighed amount of glucose is shown in the composite curve of nine normal dogs (Fig. 1). Note the rapid rise during the first hour from .09 to 133 and the equally steady drop to the normal.

Compare the normal curve with the blood sugar curve of the normal dog after thyroidectomy (Fig. 2). Note the slow absorption and the slow output showing, if figures and experiments can show anything, that tremendous

a

change has come over the dog, so far as his sugar metabolism is concerned with the removal of his thyroid.

If we study other curves of thyroidectomized dogs we find the same condition prevailing, the rapid intake during the first hour in the normal dog and the slow, gradual intake and equally slow output following. The amount of blood sugar in the cretinized animal never reaching the amount in the normal animal, but the retention lasting over a much longer period.

Janney concludes, therefore, that cessation of the thyroid function results in hypoglycemia and delayed removal of sugar from the blood, may we expect, on the other hand, that a hyperthyroid condition will result in an exactly opposite condition? If this is so and if it can be proved to be a constant occurrence it is readily seen that we have a most useful method for determining our thyroid function. The blood sugar curves of exopthalmic goitre before and after treatment (Fig. 3) show graphically the sudden, sharp rise and sharp fall that is indicative of the sugar intolerance of this disease.

How useful the application of these facts has proved in our work at the San Francisco Hospital for Tuberculosis I shall show later. Another means of identifying a hyperactivity of the thyroid is that a constant manifestation of thyrotoxicosis is a rise in the general heat production.

Means and Aub, Jour. A. M. A., July, 1917, have made a large number of observations on the metabolism of goitre patients under different modes of treatment and their results are most interesting.

The patient's heat production is measured by calculation from his gas exchange, which is determined by Benedict's respiration apparatus. By indirect calorimetry the number of calories produced can be calculated, pro