REVIEW XI.

1. Ueber die Wirkung warmer Sitzbäder. Von Dr. L. LEHMANN. (Archiv des Vereins für gemeinschaftliche Arbeiten zur Förderung der wissenchaftliche Heilkunde,' Band i. p. 521; Band ii. p. 1.) On the Effect of Warm Sitz-baths. By Dr. L. LEHMANN.

2. Die Sooltherme zu Bad Oeynhausen (Rehme) und das gewohnliche Wasser. Von Dr. L. LEHMANN.-Göttingen, 1856. The Saline Baths of Oeynhausen and Ordinary Water.

LEHMANN.

By Dr. L. 3. Das Thermalbad in Bad Oeynhausen. Von Dr. L. LEHMANN. (Archiv des Vereins,' Band iv. p. 18.)

The Warm Bath of Oeynhausen. By Dr. LEHMANN.

4. Versuche über die physiologische Wirkung des Kochbrunnens zu Wiesbaden. (Archiv des Vereins fur wiss. Heilk.,' Band iii. p. 59.) On the Physiological Action of the Saline Baths of Wiesbaden. By Dr. NEUBAUER.

5. Die Bedeutung und der Werth arithmetischer Mittel mit besonderer Beziehung auf die neueren physiologischen Versuche zur Bestim mung des Einflusses gegebener Momente auf den Stoffwechsel. Von Professor RADICHE in Bonn. (Archiv für physiologische Heilkunde.' 1858, p. 145.)

The Importance and Value of Arithmetical Mean Values in the Determination of Certain Influences exerted upon the Metamorphosis of the Tissues. By Professor RADICHE.

THE study of the final products of tissue change (the products derived from the substances which have played their part in the stage of life, and which emerge from the skin, the lungs, the bowels, or the kidneys) has lately undergone a great development. The new modes of examining the urine, which render feasible a rapid determination of its chief ingredients, the improved appliances for collecting the perspiration, as adopted by Schottin and Funke, the greater accuracy of the mode of determining the carbonic acid and water of the breath, and the important observations of Marcet on the intestinal excretions, seem to indicate that we are approaching a time when the physician will not only be able exactly to know what enters the body, but will be able to give an accurate numerical determination of what comes out of it.

Already, especially in Germany, we see these methods applied to physiological, therapeutical, and pathological inquiries, and in the midst of much that is unsound, untrue, and misleading, it is impossible not to recognise the fact that what is virtually a new field has been thrown open for investigation, and that important discoveries may reasonably be expected. At present it is, however, desirable to observe that no little caution and careful criticism is necessary in order to prevent a flood of crude and deceptive observations overwhelming the sterling facts of acquired science. That the experiments should be exact and careful, is of course only what we expect from all who are

engaged in these inquiries. But when conscientious and exact quantitative analyses of the urine or the pulmonary excretion have been made, an incorrect way of stating the results may vitiate all the conclusions. On subjecting to a mathematical analysis some of the latest observations of the new school, Professor Radiche of Bonn* has shown that the common mode of reckoning averages is liable to grievous error, and that exacter methods of calculating results must be used if anything like mathematical certainty is to be introduced into physiologico-chemical inquiries. Some of the best conducted experiments as those of Mosler on the action of water, Beneke on sea bathing, and Kaupp on the influence of chloride of sodium on urea-are shown to be more or less vitiated by inherent errors in the mode of calculating the mean results of their experiments, so that possibly all these elaborate and apparently conclusive experiments may have to be again performed. But after careful experiments have been properly calculated, it still remains to draw well-founded conclusions; and this is a matter of such difficulty, that almost every conclusion at present come to, must be regarded as merely provisional. As an instance of our meaning, we will select one substance only, urea. Urea can now be quantitatively determined with great ease and considerable accuracy; supposing in any case that an increased amount of urea is decidedly excreted by the kidneys, such increase cannot now be held to be per se evidence of increased tissue change, as it has by some been considered to be; for it may result, 1st, merely from increased elimination, with or without previous retention; 2nd, from immediate formation of urea from food (for the vital question of the "luxus consumption" of Bidder and Schmidt is by no means settled,† and the possibility of this origin of urea cannot be disregarded); 3rd, from vicarious action when the skin is inactive, for if the late observations of Picard and Funke be correct, and if some quantity of urea is daily excreted by the healthy skin, we cannot reject the possibility of the skin and kidneys acting vicariously as regards urea, as they undoubtedly do as regards water and chloride of sodium; 4th, from increased tissue metamorphosis ; 5th, from perverted metamorphosis, for it appears probable that a portion of the albuminous food and tissues normally runs through a series of metamorphoses which end in eliminating its nitrogen as ammonia, and this portion may conceivably vary in amount, It is obvious, therefore, that in many cases the cause of an increased excretion of urea will be determined with great difficulty, and conclusions must be drawn with the utmost caution.

The difficulties with other excreta are scarcely less formidable, and in fact it may be said that absolutely certain results will not be arrived at until all the products passing off from all channels (skin, kidneys, lungs, and bowels) can be quantitatively determined during the same

Die Bedeutung und der Werth arithmetischer Mittel, Archiv für phys. Heilk., 1858, p. 145.

The arguments of F. Führer and H. Ludwig (Die Quellen des Harnstoffs, Archiv fur phys. Heilk., 1855, p. 491,) seem to us very strong against the view of Bischoff and Liebig, even if they do not prove the writers' own view of the part played by the red corpuscles.

period. At present this perfection of analysis has not been attained, though we appear certainly to be approaching it.

We have made these few remarks before proceeding to bring before our readers some of the late inquiries conducted on the plan now referred to. Did we not believe that these inquiries are really of great value, in spite of the errors and inconsistencies which are obvious in them, we should not think of requesting the serious attention of our readers. But we do believe that as microscopic research has been the character of the last fifteen years, and as molecular chemistry and molecular physics (if we may use the term) will be the great object of the next generation of physicians, so an era of chemical inquiries is commencing for us, which, like the microscope, must contribute its share towards the formation of the exacter science which it is not too much to hope is dawning upon us.

On the present occasion we have selected for our subject the influence of BATHS, and we proceed to analyse the chief papers which during the last three or four years have been published on this head.

The writer who has contributed most largely to this subject is Dr. Julius Lehmann (a namesake of the great physiological chemist), an observer whose name we have had to quote several times in this journal in connexion with inquiries of a like kind. Dr. J. Lehmann is evidently not only an industrious but an accurate man, and we believe we may safely accept the record of his experiments as conscientious and true.

1. Hip Baths.-Lehmann's earliest experiments were with Cold Hip (sitz) Baths,* and were conducted as follows. During six fasting hours on eight days, the exact loss of weight of the body (caused by the constant elimination without fresh supply of food), and the exact amount of urine and fæces, were determined. The weight of the urine and fæces deducted from the total loss of weight of the body at the end of the period of experiment, gave of course the loss by "insensible perspiration."+ During eight other days, one or two cold sitz baths (fifteen minutes) were taken during the six hours; the loss of body-weight, the amount of urine, fæces, and insensible perspiration, were again determined. The two series were then compared. We give the mean results:

The mean loss of weight in each six hours was,

The loss produced by the fasting alone was thus made up—

Archiv des Veriens für wissenschaftl. Heilk., Band i. p. 521. The water in the sitzbath covers the upper parts of the thighs and the body to just above the pelvis.

↑ The "insensible perspiration" is a term usually employed to denote the quantity of all the products passing off by the skin and lungs.

The increase in the urine was owing partly to increased flow of water (), partly to augmented discharge of solids. The increase in the solids was owing to urea in great measure (), and then to chloride of sodium; the sulphuric acid was unaltered; the phosphoric acid rather lessened; the uric acid was only altered in so narrow a limit as to be within the range of error of observation.

Such, then, are the mean results; now, what are they worth? We admit at once that the experiments were exact, and that really this increase did occur. But was it owing to the baths, or to some one or more of the other influences (external temperature, movement, nervous action, &c.), which are constantly acting on the metamorphosis of tissue?

The first objection, and, to our minds, a fatal one, is the circumstance that the experiments were not made on successive days, but were scattered over an interval of nearly four months, some experiments being conducted in July, others in August, September, October, and November. Nothing can be more fallacious than such a method, as the amount of urine is subject to great and even periodical changes,* and by selecting a day here and there, we may chance to hit on one of the greatest deviations from the mean. Secondly, the number of days (eight) is not sufficient to allow a true mean to be drawn. On this point opinions have lately undergone some development, and it is now generally considered that observations must be carried on for many days (twenty or thirty at the least) before a sufficiently correct mean is arrived at, unless in cases in which, as in disease, deviations so enormous as to preclude the idea of error, occur from the mean. Thirdly, on subjecting some of Lehmann's daily observations (from which the mean is drawn) to an analysis similar to that recommended by Radiche, we find the possible errors to be so great, as to render any decided deductions hazardous. The utmost that can be said is, that there is a probability

A certain periodical or wave-like increase and decrease in the urinary excretion was affirmed by the writer of this Review, in the Gulstonian lectures for 1855. Radiche from his calculations, and Vierordt from independent observation, have lately stated the same fact. If an experimenter on the urine happens to take a day at the ebb, or at the full flow of the wave, how different would be the result from the real average amount.

We have, in fact, only calculated the possible errors in one ingredient, viz., the water of the urine, as we thought it unnecessary to take further trouble. We may briefly sketch the result:

The measured quantity of urine on each of the non-bathing days amounted during the six hours in cubic centimetres to 201:35, 274-8, 226-8, 364, 194, 282-6, 290-85, 341-5. The successive means (obtained by taking the means first of the two first days, then of the three first, of the four first, and so on) are 238-075, 234-316, 266,737, 252-19, 257-26, 262-06, 271 98. The probable mean (mean of six last successive means), may be taken as 262 (10 c. e. under the mean given by Lehmann). The mean variations from this quantity may be taken as 60 c. c.

The measured quantity of urine on each of the bath days was, during the six hours,

(the extent of which is scarcely worth numerical expression) of the effect of the cold sitz bath being really that assigned to it. If, indeed, other observations conducted on a larger scale should accord with these, it would give them more weight.

We will, then, pass on to further observations. Dr. J. Lehmann's second inquiry was into the effect of warm sitz-baths.* The experiments were made in a somewhat different manner. The amount of urine was determined every hour. As long as no food and no great exercise were taken, when nothing, in fact, disturbed the normal metamorphosis, the flow of urine was so stable, that Lehmann found the amount of any two hours multiplied by three, gave always very closely the amount for six hours. If now during such a stable excretion a fresh agent is employed, and if any great change, either in the urine or other excretions, occurs, it is but right to refer it to the action of the agent; and if in experiment after experiment the same result is found to occur, the cogency of proof becomes at last very great.

Conducted in this manner, Lehmann's experiments led him to the following conclusions: The waste of the body was increased by 15 minutes' sitz-bath of temperatures of 15° R. (65°-75 Fahr.), and of 25°— 31° Reaumur (88° to 990.5 Fahr.); and this waste was produced by an increased excretion of urinary water and of solids (urea, uric acid, fire-proof salts, and chlorine). But the surprising fact was discovered, that baths of a medium temperature (17°—25° R., 70°-88° Fahr.) did not have this effect. Excretion, therefore, according to Lehmann, is increased by sitz-baths below 70° Fahr., by sitz-baths above 88° Fahr., but not by baths between 70° and 88°.

We have already seen reason to call in question the experiments supposed to prove the first opinion, and the singular difference of effect attributed to lukewarm and hot baths, makes us very suspicious of this inquiry also. On going over the items of the experiments, however, we do not observe any obvious fallacy: six hours on five days were occupied with the hot-bath experiments; the excretion of the two first hours being taken as the standard in all the cases the urinary flow was greatly and immediately augmented, rising from 30 or 50 c. c. per hour to 90, 100, or even 150 c.c. Nor for this great increase does there appear to have been any other cause than the baths. Yet it must be said that the experiments are not sufficiently numerous, and on this ground it is advisable to defer our judgment,

334-4, 674, 280, 200, 601, 364, 583-2, 668-2; the successive means are, 504·2, 427·1, 372·1, 417-7, 4089, 433-8, 463-1. The probable mean may be taken as 431; the mean variation as 180.

The difference between 262 and 431, the received means of the two series, is very considerable, viz., 169 c. c. in favour of the bath-days, and does at first sight appear to justify Lehmann's conclusion, but, owing to the great inequality of the quantities on different days, the range of error is so enormous (the variation being 60+180=240) as to render a certain conclusion quite impossible.

Ueber die Wirksamkeit 15-30-5 Reaumur warmer Sitz-Bäder. Archiv des Vereins für wiss. Heilk., Band ii. p. 1

† Lehmann states (p. 19) that the insensible perspiration (skin and lungs) is also increased, but this does not appear from the table given at p. 10; the mean amount of insensible perspiration is even a little less with baths of 25 -30°5 R. than without baths.