sened, which does not look like an increase of creatine or creatinin.

4. The uric acid was found to be decreased slightly by Böcker; largely, by Hammond.

5. The sulphuric acid was found to be immaterially lessened by Hammond.

6. The phosphoric acid was largely decreased in Böcker's and Lehmann's experiments. In Hammond's it was normal. Further experiments on this point (a very interesting one in connection with the metamorphoses of the nervous system) are much needed.

7. The chlorine was found to be much lessened by all three observers.

8. The condition of the bases (potash, soda, lime, magnesia, and ammonia) is not known.

These results are attributable, by L. Lehmann, chiefly to the essential oil. Caffein produces the same effects, but in a much less degree. The nervous symptoms (tremors, increased cardiac action, &c.) are usually ascribed to the caffein. The pulmonary carbonic acid is, according to Edward Smith, increased by coffee as by tea. In dogs, Hoppe has also noticed an increase; so that in this case the alterations in the urea and pulmonary CO2 do not run parallel.

VIII. COCOA AND CHOCOLATE.

It is supposed that these substances have the same effect as coffee, but exact experiments on the urine have not yet been made.1

IX. PERUVIAN COCA (ERYTHROXYLON COCA).

The remarkable dietetic effects of the Erythroxylon coca 2 have led to the belief that it must limit the metamorphosis of tissue. Its power on the nervous system is evidently analogous to that of hemp and opium, and it also, after a time, weakens the digestive organs, and deranges greatly the action of the liver. The condition of the urine has not been properly examined, and it cannot be said whether or not there is any alteration in it.

1 The little work of A. Mitscherlich (Der Cacoa und die Chocolat, 1859), the last on the subject I can find, contains nothing bearing on this point.

A very full and interesting account of Poeppig's statements on this subject, which all succeeding writers have quoted, will be found in Sir William Hooker's Companion to the Botanical Magazine, 1835, p. 161, for a reference to which I am indebted to Dr. Joseph Hooker. Reference can be made also to Johnston's Chemistry of Common Life.

The latest writer on the subject, Mantegazza, states that the urine is increased; but no analyses are given, and the assertion is not more worthy of credit than those which have been made in a contrary sense.

The various liquids ordinarily taken as food? are thus divisible. into two great classes, those which favour, and those which more or less retard, urinary excretion. To the first class belong water and the lighter wines; to the second, alcohol, strong wines (probably), strong beer, tea, and coffee. The retardation of excretion produced by the second class is, however, not shown merely by the urine, but in several cases also by the pulmonary, the cutaneous, or the intestinal excretions. It can, therefore, scarcely be doubted that the action of these substances is not merely that of retaining certain excretions in the body, but that of absolutely lessening their formation. They appear, in fact, to retard metamorphosis, though in different degrees and in different directions; some acting remarkably on the urine, but less on the intestines, as coffee; others influencing the urine very little, but the bowels more, as tea. These substances differ also in their mode of action, even on the urine : thus tea appears to slightly lessen the uric and the phosphoric acids, while it scarcely affects the urea; while coffee not only affects the chloride of sodium, but lowers remarkably the urea, the uric acid, and (probably) the phosphoric acid. No doubt also other differences will be made out, and each substance will be found to have its specific action.

Although the effect on the urine of these substances is thus tolerably well known in systems which are carefully arranged for the experiment, it remains to be seen how far in actual life their effects are counteracted by custom, habits, or peculiarities of race and climate. It is impossible to suppose that every drinker of spirits has always such a small excretion as occurs in the temperate man, who suddenly (for the sake of the experiment) introduces a large quantity of alcohol into his body. The effect of the alcohol may be counteracted by other conditions, such as the use also of large quantities of water, of great exercise, or like agencies, which augment metamorphosis.

The exact steps of the process by which this retardation of metamorphosis is brought about are not yet known; we see only the results. Is it from simple appropriation of oxygen, or from some more complex action of nutrition directly, or through the medium of the nerves? Is the process of the building of the

Schmidt's Jahrb., 1859, No. 12, p. 349.

2 I have not alluded to milk or whey, as I am unacquainted with any trustworthy experiments on the urine.

tissues equally delayed with that of their unbuilding? In many cases, the use of these agents in large quantities lessens the desire for food, and the body maintains its weight on less nutriment than would have been the case with water or light wines.

How far this result is a good one-how far the normal rapidity of metamorphosis (such as occurs with moderate water-drinking) can be advantageously checked by the use of such substances-is a social problem of the highest importance. It seems to me, that the obvious deduction from our present physiological knowledge is, that the more rapid the healthy metamorphosis of the body, within certain limits, the more urea and pigment are formed, the more perfect is nutrition, as long as nutriment is supplied in sufficient amount, and as long as the formative powers can use it. In the immense excretion of children, and in the retarded metamorphosis of old age, we see the two ends of the scale, and have the proof that growth and progress are corollaries of rapid metamorphosis and elimination. Have we then a right to conclude, that anything which impedes healthy metamorphosis is hurtful, and that, in checking disintegration, it will equally check formation? Perhaps, without going at present quite to this length, we may believe that the most perfect condition of health is rapid building and rapid unbuilding; and all the most strengthening hygienic means, as exercise, sea air, saline baths, and abundant nutritious animal food, act by forwarding both these processes. Appetite increases, but at the same time the action of the eliminating organs is also increased; the body gains weight, although there must be increased rapidity of the molecular currents and of chemical changes.

The training for the ring may be taken as an illustration of my meaning. The prize-fighter eats largely of animal food; he thus, if Bischoff's and Voit's experiments be received, increases both the formation and the disintegration of tissue; and it is to be presumed, that the excretion of urea during training must be increased. The prize-fighter brings into play another factor of elimination, for he gradually increases his muscular movements to an enormous extent; and, by so doing, he must absorb much more oxygen than usual, and give out more carbonic acid. (Seguin, Hoffman, Vierordt, E. Smith.)

All the three great factors of metamorphosis, viz., nitrogenous food, oxygen, and movements, are thus increased; and the amount of metamorphosis must also go on augmenting, up to a certain point, as the bulk of the tissues increases.

So far the prize-fighter may be said to follow the dictates of common sense; but now how does he act with regard to alcohol, and wine, and the substances usually supposed to give strength, and to limit the necessity for food? Why he almost discards

their use; he takes no spirits, no wine, only a little weak beer (which he might with advantage leave off); but drinks to any amount of pure water, or fluids equivalent to it; and thus taught by experience, he employs another most potent agent in elimination.

Under this regime, his health improves wonderfully; he can bear any fatigue, morbific causes are comparatively inoperative, injuries are more easily recovered from, and, for the time, he is the very type of health and vigour. That the class is not a healthy one, is owing to the reckless living between the periods of training.1

If, then, nitrogenous food is abundant, the use of substances to check metamorphosis, within physiological limits, seems unphilosophical. If the food be insufficient, then the use of these substances may become desirable. Yet, as Liebig says, the use of alcohol, coffee, tea, and such substances, is so universal as to look like an instinct; and some decided benefit must be at the bottom of a custom so general. The explanation usually given, that these substances are taken, because, by lessening metamorphosis, they lessen the desire for food, and maintain the body at the same weight with less nutriment, may account for some but not for all cases; and it is most probable that their immediate sensible effect on the nervous system is that which is wished for by those who take them, and that, as already said, any part of their action which might be injurious is commonly counteracted by other habits which are almost as instinctively adopted as is the use of these substances themselves. Yet I must candidly say, with regard to the stronger alcoholic liquids, that what study I have been able to give to this subject, and to the causation and treatment of disease generally, have led me more and more to adopt the view of Carpenter and others, and to believe that the use of alcohol in health is not only unnecessary, but is absolutely injurious. The effect of light wine, beer, tea, and coffee, in impeding metamorphosis, is, however, so inconsiderable, and their irritating effects on tissues are so slight, that there seems nothing to urge against their moderate use.

Whatever may be the difficulties, at present, of discussing this most important dietetic subject in the case of healthy persons, there can be no doubt that what is known of the action of these substances assists us very much in using them in disease. The

1 These remarks were written long before the late prize-fight so strongly directed the public attention to the effects of training. In the Lancet, and other journals, most sensible remarks have been made on this point; and if the attention of the profession is directed to the true sources of strength of body (which will not be found in the use of alcohol), this celebrated contest will have done much good.

2 I may refer to an interesting article on tea, coffee, &c., by Dr. King Chambers, in the B. and F. Med..Chir. Rev., 1854.

nervous system is stimulated, and metamorphosis lessened, by coffee, and slightly by tea; and in exhausting diseases these effects are most useful.

I presume that, while sugar, starch, &c., are available, it can seldom be necessary to employ alcohol as a factor of heat; this object can be obtained by more easy and more certain methods. The physician, as I take it, uses alcohol for two great purposes as a direct stimulus to the weakened stomach, and as a stimulant of the nervous system, and, through it, of the failing heart. Now, in our choice of alcoholic fluids, we must be guided, it appears to me, by the consideration of how far it is wished, at the same time, to check or to increase elimination. For example, in the last stages of fever, when the body has wasted almost to extremity, and when, as the controlling power of the nervous system is lost, too great disintegration may still go on, even in the emaciated tissues, pure alcohol, which stimulates the heart's action, and yet impedes metamorphosis, must be employed; while, in other cases, in which, while the nervous system and the heart must be stimulated, it is desired not to check excretion (as during the absorption of exudations), the lighter wines, or the combination of spirit with alkaline salts, should be chosen. In the vast class of chronic complaints dependent on lesions of nutrition, obstinate congestions, and continued parenchymatous inflammation, and in which, as a rule, digestion is weak and tissue change is lessened, the same rules hold good; and, by a judicious combination of means, we may obtain from these substances the effects we desire from them, and can counteract and nullify the influences which should be avoided.

SECTION IX.

FASTING.

Fasting may consist in abstinence from solids or liquids generally, or from one or more special ingredients of the diet. The influence of food usually ceases in about twelve hours (Falck), and after that time the urine represents only tissue metamorphosis (urina sanguinis, or urine of inanition). Occasionally the influence of food lasts for sixteen or twenty hours

This opinion is not that of the late Dr. Todd, who emphatically recommended alcohol as a food. But its local irritating effects on the liver and nervous tissues seem to me to render it as undesirable a food as can well be named, unless those irritating properties are expressly desired; while the evidence of its destruction in the system is, as already said, very incomplete. We know only that, if destroyed, it is so only partially, and with difficulty. Its rank as a heat-giving food cannot be high, if indeed it be a food at all.