most of the table waters of commerce do, the presence of the alkali quite removes this retarding effect.

'The use of these waters as an addition to wines is,' Sir William Roberts observes, highly commendable,' as they 'greatly mitigate or wholly obviate the retarding influence of these wines on the digestion of starch.'

It was also observed that these weaker forms of alcoholic drinks (wines and beer) differed greatly in their influence on peptic digestion to that of the distilled spirits. They retarded it altogether out of proportion to the quantity of alcohol they contained. Port and sherry exercised a great retarding effect. Even in the proportion of twenty per cent. sherry trebled the time in which digestion was completed.' It should further be borne in mind that this wine also retards greatly salivary digestion. Sherry, then, is not a suitable wine for persons of feeble digestive powers.

With hock, claret, and champagne it was also ascertained that their retarding effect on digestion was out of proportion to the alcohol. contained in them; but champagne was found to have a markedly less retarding effect than hock and claret ;' indeed, in the proportion of ten per cent. champagne had a distinct, though slight, accelerating effect, and this superiority of champagne appears to be due to the 'mechanical effects of its effervescent qualities.'

The quantity of claret and hock often consumed by many persons at meals must exercise a considerable retarding effect on peptic digestion; but small quantities of these wines (and even of sherry) do not produce any appreciable retarding effect, but act as pure stimulants. These wines, then, may be taken with advantage, even by persons of feeble digestion, in small quantities, but not in large.

With regard to malt liquors, it was observed, as with wines, that they retarded peptic digestion in a degree altogether out of proportion to the amount of alcohol contained in them, and when taken in large quantities they must greatly retard the digestion, especially of farinaceous food; but a moderate quantity of light beer, when 'well up,' is favourable to stomach digestion.

It was proved by these experiments that the sparkling wines impede digestion less than the still ones, and when taken in moderate quantity act not only as stimulants to the secretion of gastric juice and to the muscular activity of the viscus, but may, at the same time, slightly accelerate the speed of the chemical process in the stomach.' Next as to the influence of tea, coffee, and cocoa on the digestive processes.

Tea exerts a powerful retarding influence on salivary digestion, coffee and cocoa a comparatively feeble one.

Sir W. Roberts estimates the medium strength of the tea usually drunk at four to five per cent.; strong tea may contain as much as

seven per cent., weak tea as little as two per cent. Medium coffee has a strength of about seven per cent., and strong coffee twelve to fifteen per cent.; cocoa, on the other hand, is generally weaker, not more than about two per cent., and this, he thinks, may be one reason why it is more suitable to persons with feeble digestions than tea or coffee.

Tea exercises a powerful inhibitory effect on salivary digestion, and this appears to be entirely due to the large quantity of tannin it contains.

It appears that tannin exists in two conditions in the tea leaf. One, the larger portion, is in the free state and is easily extracted by hot water; but about onefourth is fixed and remains undissolved in the fully exhausted tea leaves. Some persons have supposed that by infusing tea for a very short time—only two or three minutes the passing of tannin into the infusion would be avoided. This is a delusion; you can no more have tea without tannin than you can have wine without alcohol. Tannin, in the free state, is one of the most soluble substances known. If you pour hot water on a little heap of tannin it dissolves like so much pounded sugar. Tea infused for two minutes was not found sensibly inferior in its retarding power on salivary digestion to tea infused for thirty minutes.

One gentleman of my acquaintance (says Sir W. Roberts) in his horror of tannin was in the habit of preparing his tea by placing the dry leaves on a paper filter and simply pouring on the boiling water. In this way he thought to evade the presence of tannin in his tea. But if you try the experiment, and allow the product, as it runs through the filter, to fall into a solution of perchloride of iron, you will find that an intense inky black coloration is produced, showing that tannin has come through in abundance.

In order to diminish as far as possible the retarding influence of tea on salivary digestion, it should be made weak and used sparingly, and it should not be taken with but after the meal.

There is another means, mentioned by Sir W. Roberts, of obviating the retarding effect of tea on salivary digestion, and commended by him to the dyspeptic; it is to add a pinch of bicarbonate of soda to the tea when it is being infused in the tea-pot. He found that ten grains of soda added to an ounce of dry tea almost entirely removed this retarding influence. The infusion thus made is darker than usual, but the flavour is not sensibly altered, nor is the infusion rendered alkaline, for tea infusion is naturally slightly acid, and the soda, in the proportion mentioned, only just neutralises this acidity.

Coffee, unless taken in very large quantity, has very little retarding effect on salivary digestion; this is explained by the fact that the tannin of tea is replaced in coffee by a substance called caffeo-tannic acid. Cocoa resembles coffee and has little or no effect on salivary digestion; the use of coffee or cocoa is therefore preferable to that of tea for persons of feeble digestion.

With respect to the influence of tea and coffee on stomach digestion, it was found that they both exercised a remarkable retarding effect.

There was no appreciable difference in the two beverages if they were of equal strength; but as coffee is usually made of greater percentage strength than tea, its effect must ordinarily be greater. Cocoa also had much the same effect if used of the same strength as tea or coffee, but when of the strength ordinarily employed its effect was inconsiderable. Strong coffee-café noir-had a very powerful retarding effect, and persons of weak digestion should avoid the customary cup of black coffee' after dinner.

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'I could not detect,' says Sir W. Roberts, ' any appreciable difference between the effect of tea infused for two or three minutes and tea infused for fifteen or thirty minutes. If you wish to minimise the retarding effects of tea in persons of weak digestion, you should give instructions that the beverage be made weak, or that it be used in sparing quantities.' And he adds in a foot note, 'A good deal has been said of the injurious effects on gastric digestion of tannin contained in tea. I question whether the statements made with reference to this matter are worthy of attention. It has been alleged that meat fibre is hardened by tea, and that the coats of the stomach are liable to be injured by this beverage. These views are entirely theoretical' (p. 48).

Perhaps one of the most unexpected results of these experiments of Sir W. Roberts was the discovery that beef tea had a powerful retarding effect on peptic digestion, as much so as that of a five per cent. infusion of tea. Further researches appeared to show that this retarding effect of beef tea was due to the salts of the organic acids contained in it.

While on the subject of beef tea it will be novel and instructive to many to hear that

there is a widespread misapprehension among the public in regard to the nutritive value of beef tea. The notion prevails that the nourishing qualities of the meat pass into the decoction, and that the dry, hard remnant of meat fibre which remains undissolved is exhausted of its nutritive properties; and this latter is often thrown away as useless. A deplorable amount of waste arises from the prevalence of this erroneous notion. The proteid matter of meat is quite insoluble in boiling water, or in water heated above 160° F. The ingredients that pass into solution are the sapid extractives and salines of the meat, and nothing more except some trifling amount of gelatine. The meat remnant, on the other hand, contains the real nutriment of the meat, and if this be beaten to a paste with a spoon or pounded in a mortar and duly flavoured with salt and other condiments, it constitutes not only a highly nourishing and agreeable but also an exceedingly digestible form of food.3

Beef tea must therefore be looked upon rather as a stimulant and restorative than as a nutrient beverage, but it is nevertheless very valuable on account of those properties.

These remarks on beef tea apply equally to Liebig's extract of meat, Brand's essence of beef, and Valentine's meat juice, all of which are devoid of albuminous constituents' (British Medical Journal, August, 1885).

Sir W. Roberts puts forward an ingenious argument, which cannot be fully repeated here, in favour of the view that, in healthy and strong persons, this retarding effect on digestion observed to be produced by many of the most commonly consumed food accessories answers a distinctly useful end. They serve, he maintains, the purpose of wholesomely slowing the otherwise too rapid digestion and absorption of copious meals.

A too rapid digestion and absorption of food may be compared to feeding a fire with straw instead of with slower-burning coal. In the former case it would be necessary to feed often and often, and the process would be wasteful of the fuel; for the short-lived blaze would carry most of the heat up the chimney. To burn fuel economically, and to utilise the heat to the utmost, the fire must be damped down, so as to ensure slow as well as complete combustion. So with human digestion: our highly prepared and highly cooked food requires, in the healthy and vigorous, that the digestive fires should be damped down, in order to ensure the economical use of food. . . . We render food by preparation as capable as possible of being completely exhausted of its nutrient properties; and, on the other hand to prevent this nutrient matter from being wastefully hurried through the body we make use of agents which abate the speed of digestion.

It must be borne in mind that these remarks apply only to those who possess a healthy and active digestion. To the feeble and dyspeptic any food accessory which adds to the labour and prolongs the time of digestion must be prejudicial; and it is a matter of common experience that beverages which in quantity retard digestion have to be avoided altogether by such persons or partaken of very sparingly.

In the dietetic use of wines the writer of this article has constantly had occasion to make the observation that those wines agree best and are most useful which are absorbed and eliminated from the system with the greatest rapidity, as tested by the increase of the renal secretions, and he has been led to the practical conclusion that this is the best criterion of the suitability of any particular wine to any particular constitution. If the effect of different wines on notoriously gouty persons be carefully observed, it will be found that some can drink champagne (in moderation of course) with impunity, especially if a small quantity of an effervescing alkaline water be added to it, while claret will at once provoke some manifestations of gout; others who are unable to drink champagne without provoking a gouty paroxysm will often be able to drink a mature, fine, soft claret even with advantage; others will support hock well, and a few can drink fine sherries and ports in small quantities; but in all it will be found that the test of the suitability of the particular wine to the particular constitution is its susceptibility to rapid elimination and vice versa.

It has occurred also to the writer to make many observations as

to the circumstances under which tea and coffee are found to agree or disagree with different persons; in the first place, as Sir W. Roberts has pointed out, tea, if taken at the same time as farinaceous food, is much more likely to retard its digestion and cause dyspepsia than if taken a little time after eating; and the custom adopted by many persons at breakfast, for instance, of eating first and drinking their tea or coffee afterwards is a sensible one; so also it is better to take one's five o'clock tea without the customary bread-and-butter or cake than with it.

Indeed, while there is little that can be said against a cup of hot tea as a stimulant and restorative, when taken about midway between lunch and dinner, and without solid food, it may, on the other hand, be a fruitful cause of dyspepsia when accompanied at that time with solid food. It is also a curious fact that many persons with whom tea, under ordinary circumstances, will agree exceedingly well, will become the subjects of a tea dyspepsia if they drink this beverage at a time when they may be suffering from mental worry or emotional disturbance.

Moreover it is a well-recognised fact that persons who are prone to nervous excitement of the circulation and palpitations of the heart have these symptoms greatly aggravated if they persist in the use of tea or coffee as beverages. The excessive consumption of tea amongst the women of the poorer classes is the cause of much of the so-called heart complaints' amongst them: the food of those poor women consists largely of starchy substances (bread-and-butter chiefly) together with tea, i.e. a food accessory which is one of the greatest of all retarders of the digestion of starchy food.

The effect of coffee as a retarder of stomach digestion would probably be more felt than it is were it not so constantly the practice to take it only in small quantity after a very large meal; it is then mixed with an immense bulk of food, and its relative percentage proportion rendered insignificant; and to the strong and vigorous the slightly retarding effect on digestion it would then have may be, as Sir W. Roberts suggests, not altogether a disadvantage; but after a spare meal and in persons of feeble digestive power the cup of black coffee would probably exercise a retarding effect on digestion which might prove harmful. It is also worthy of remark that in the great coffee-drinking countries this beverage is made not nearly so strong as with us. In this country good coffee always means strong, often very strong coffee; but on the Continent they possess the faculty of making good coffee which is not necessarily very strong coffee, and which is, therefore, as a beverage, less likely to do harm.

The general conclusion to be drawn from these highly interesting and instructive researches is that most of the food accessories' which in the course of civilisation man has added to his diet are, when