from which the cream had been most carefully removed after the milk had remained in a cold situation twenty-four hours. All other food was strictly prohibited, and neither claret nor other drink was taken. Under this treatment the quantity of fatty matter taken in the milk must have been extremely small. The following table shows the effect produced on the urine :—

On the 21st of April the quantity of sugar in the urine was reduced to a mere trace.

The results obtained by these two experiments on the same individual are to my mind perfectly conclusive, that fatty matter taken as food increases the

amount of diabetic sugar in the urine after the disease has continued some length of time. I have met with other instances corroborative of this opinion. Thus, in a case of long-standing diabetes placed under the skim-milk treatment, the specific gravity of the urine never fell below 1025, and very seldom so low, as long as the milk stood only eight or twelve hours before the cream was separated; but no sooner was the milk allowed to stand twenty-four hours before it was skimmed and used, than under its influence the specific gravity of the urine fell to 1019 and the sugar to one-half the previous amount.

In another instance, to be referred to further on, the administration of new milk, rich in cream, caused a return of sugar in the urine about a fortnight after its removal by the skim-milk treatment.

If further evidence was necessary to prove that fat contributes to the formation of sugar in diabetes, it is supplied by the experiments of Dr. Pavy on the administration of glycerine and of a diet composed of milk (containing the cream) and suet. To these experiments I must now refer.

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As glycerine does not belong to the carbo-hydrate group, its composition being: Cg Hg Og, Dr. Pavy considered it would not be expected to produce an increased elimination of sugar. On making a trial

with it, however, the result was exactly opposite to what he anticipated. I shall here, in his own words, give his account of the experiment: To a patient who was being restricted to an animal diet, and who was passing from three to three and a half pints of urine, and from 900 to a little over 1,100 grains of sugar in the twenty-four hours, I ordered glycerine to be administered. Upon the first day he took six ounces; upon the second, eight ounces; and upon the third, ten ounces. The urine rose in quantity to between five and six pints, and the sugar to from upwards of 2,000 to upwards of 3,000 grains per diem. glycerine being omitted, the urine immediately fell in quantity and averaged for several days about three pints, and the sugar about 1,500 grains. Glycerine was then given again to the extent of ten ounces a day for two days consecutively. The urine rose, and upon the third day reached eight pints, and the fourth day seven and three quarter pints in quantity. The sugar upon the first day amounted to 3,744 grains; the second, 4,032 grains; the third, 4,608 grains; and the fourth, 4,850 grains.

The

'The glycerine being now discontinued, the urine on the following day stood at three pints, and the sugar at 2,540 grains. The next day the urine 1 Op. cit. p. 258.

amounted only to two and a quarter pints, and the sugar to 1,199 grains. The glycerine employed was that supplied to Guy's Hospital dispensary.' Dr. Pavy adds that, whatever the explanation may be, the fact is indisputable that glycerine produced a material aggravation of the symptoms under which the patient laboured, in addition to the great increase of sugar in the urine.

Dr. Pavy made a series of experiments on a diabetic patient named North, extending over a period of nearly two months, with the view of determining the effect of various kinds of food on the quantity of sugar excreted in the urine. During the course of these experiments, when (on the 15th of February) the patient was on a diet composed exclusively of meat, jelly, and beef tea, and was passing 569 grains of sugar in the twenty-four hours, milk to the extent of three pints daily was given with the meat, instead of the jelly and beef tea, for two consecutive days (16th and 17th of February): the result was that the quantity of sugar gradually rose, and at the end of the second day amounted to 1,258 grains in the twentyfour hours. During the next three days (18th, 19th, and 20th of February) suet was added to the meat and milk diet-half a pound on the first day, threequarters of a pound on the second, and a quarter of

a pound on the third-and the effect of this addition of fatty matter was to increase the quantity of urine sugar gradually until it amounted to 2,225 grains, in the twenty-four hours, at the end of this period. On the following day (21st February) eggs and beef tea were substituted for the milk and suet, which were withdrawn, and the quantity of urine sugar fell to 927 grains.

In this experiment it is obvious: first, that the addition of milk to the patient's diet greatly increased the quantity of sugar eliminated; and secondly, that the increase was greatly augmented, or nearly doubled, by the further addition of suet.

That the special ingredient of milk which in this instance increased the amount of sugar was butter, is abundantly proved by my own numerous experiments, which have most fully established the fact that an exclusive diet of skim milk (from which the butter has been almost completely removed) rapidly and invariably diminishes the sugar in the urine, and, in a large proportion of cases, ultimately removes it altogether.

It appears to me that the only legitimate interpretation of the result obtained in Dr. Pavy's case is, that the butter of the milk raised the quantity of sugar to a certain extent, and that the further addi