whether it only takes place in consequence of the state of the blood due to the renal or other disease present; in other words, do the medicines chosen for experiment act by themselves on the kidneys, or is that changed condition of the blood and of the whole secreting structure of the kidneys, comprised in the idea of disease, necessary in order that diuresis may be produced?

If these substances were found to act as diuretics in health, the former supposition would receive considerable support. Each set of experiments was conducted under similar conditions of diet and exercise, and lasted about twenty-eight days, on the middle twelve of which the medicine under examination was taken, the medicine-free days before and after this period affording a standard for comparison. Throughout the observations the urine was examined each morning at half-past eight o'clock, from which time the twenty-four hours was reckoned, and the urea and solids determined, the former by Liebig's process, the latter by evaporation and weighing.

Citrate of Potash.

The experiments forming the basis of Tables I and II, were made during the warm summer weather; the former contains the results of the analysis of the urine during twelve days, on which no medicine was taken. On July 6th a rather larger quantity of animal food than usual was consumed, which may probably account, in some measure, for the large amount of the solids. Table II contains the analysis of the urine for twelve days, on which citrate of potash was taken in doses varying from a scruple to a dram at intervals, amounting in the twenty-four hours to from 2 to 4 drams.

On comparing the means of the tables a slight increase in the water in No. II is seen.

The urea and solids are actually diminished whilst taking citrate of potash, the former by 54, the latter by 4 grammes,

in the twenty-four hours. This reduction in the solids is very considerable, especially when allowance has been made for the carbonate of potash they contain, as the product of the decomposition of the citrate; it is possibly due to interference with digestion as well as to "an aberration, so to speak, from the normal course of metamorphosis and oxidation, which may impede the formation and elimination of urea."

Whilst taking the citrate, the urine was usually strongly alkaline, except that passed on rising in the morning, and, very frequently, turbid from the presence of phosphates.

Sp. Etheris Nitrosi (B. P.).

Tables III, IV, and V contain the series of experiments relating to nitrous ether, which was taken in water, in doses varying from 1 to 3 drams, at intervals, amounting in the twenty-four hours to from 10 to 18 drams.

Table IV gives the analysis of the urine on twelve days during which the medicine was taken.

Tables III and V contain the analyses during three and seven days, respectively before and after the period of its injection.

The experiments in table III are too few in number, and hence, in the following comparison, table V is only immediately referred to, although the result obtained is fully confirmed by a comparison of table IV with table I and with the mean of 47 medicine-free days in table XI.

Comparing, then, tables IV and V, nitrous ether would appear slightly to increase the urinary water, by 72 c.c., but to diminish the urea to the extent of 34 grammes and the solids to the amount of 8 grammes in the twenty-four hours. Perhaps this decrease in the urea and solids is due to the alcohol contained in the Sp. Etheris Nitrosi, since

1 Parkes, 'On Urine,' p. 163.

VOL. LIII.

3

the experiments of Böcker and Hammond1 show that the urea is considerably lessened by the ingestion of from 7 to 12 drams of alcohol in the twenty-four hours.

Whilst taking Sp. Etheris Nitrosi the urine was clear, acid, and free from albumen.

Acetate of Potash.

Tables V, VI, and VII contain the results of the experiments on acetate of potash.

Table VI gives the state of the urine on twelve days on which the acetate was taken, in doses varying from 20 to 40 grains, every few hours, amounting to from 2 to 3 drams in the twenty-four hours.

The salt was taken dissolved in water.

The mean excretion of water, whilst the acetate was taken, exceeds that of the seven previous medicine free days, whilst it falls below that of the six succeeding days, the excess amounting to 150 c.c., the diminution to 100 c.c. It should be observed, however, that the weather during the last six medicine free days was decidedly colder than it had hitherto been. Comparing the three tables, the urea and solids are seen to be considerably reduced, the former by from 2 to 4-4 grammes, the latter by from 7 to 6.7 grammes in the twentyfour hours. The causes of this reduction would probably be the same as in the case of citrate of potash.

These results agree generally with those of Parkes and of Böcker, except that in these experiments the solids were lessened in a far greater degree, even falling below the mean of those on the medicine-free days, notwithstanding the carbonate of potash they contained, and for which allowance must be made. This is, however, only a difference in degree; but W. Moss1 finds, as the result of his experiments, that

3 Quoted by Parkes, op. cit., p. 162.

4American Journal of Medical Science,' April, 1861.

the water, urea and solids are increased by acetate of potash. Ranke1 found the water considerably increased in one case.

Whilst taking the acetate, the urine was usually alkaline, and frequently turbid from the presence of phosphates.

Oleum Juniperi.

From

Tables VIII, IX, and X contain this series of experiments. Table VIII gives the analysis of the urine during twelve days on which the English oil of juniper was taken. 5 to 10 drops of the essence were put on sugar and taken every few hours, the total amount in the twenty-four hours being from 30 to 40 minims, a quantity representing from 25 to 33 drams of the spiritus juniperi of the British Pharmacopoeia.

On comparing the three tables it is seen that the water, whilst the oil of juniper was taken, was equal to that on the nine previous medicine free days, but fell below that on the ten succeeding days, to the amount of 160 c.c.

The urea was increased by from 6 to 1.5 grammes, and the solids by from 2 to 4.3 grammes.

Whilst the oil of juniper was taken, the urine was clear, acid, and free from albumen; it acquired a strongly aromatic odour, occasionally faintly recalling the smell of violets. The evaporated residue had also a strong and peculiar odour. No strangury or irritation of the urinary passages was experienced.

Table XI gives the mean results of the previous tables arranged together, and also the mean per twenty-four hours and the mean per one hour of the forty-seven medicine-free days occurring during the experiments. The results are stated in cubic centimeters and ounces, and in grammes and grains.

The following conclusions may be drawn from these observations :-that in health-

1 Quoted by Parkes, op. cit., p. 162.

1. Citrate and acetate of potash only slightly increase the quantity of water excreted by the kidneys.

2. They distinctly lessen the amount both of urea and of solids excreted.

3. Spiritus ætheris nitrosi slightly increases the amount of urinary water.

4. It decidedly reduces the quantity both of the urea and solids.

5. Oil of Juniper slightly reduces the amount of water excreted.

6. It appreciably increases both the urea and solids.

It would thus appear that, of these four medicines, citrate and acetate of potash and nitrous ether actually reduce the urinary solids, whilst they slightly increase the water, and that oil of juniper increases the solids whilst it slightly lessens the water.

It is evident that these experiments, performed on one. individual, will not establish generally such conclusions, but they at least show that the action of these medicines, with the exception of oil of juniper, as diuretics in health, is very uncertain.