probably its action. Sugar is a heat-giver as well as cream, whilst its caseine is a flesh-former; so that it should be remembered, in taking a cup of tea we are actually consuming one of the most compound of our foods, an article of diet which represents every group of our daily food. The Chinese do not thus adulterate their tea, and prefer, as also do our washerwomen, to take their tea pur et simple. The Russians add sugar, but either squeeze in a little lemon-juice or add a slice of lemon. This, I can assure you, is no despicable addition. When the stomach is already clogged with food, as is the case after dinner, or when thirst is best allayed by acids, then the addition of lemon or its juice is most palatable and pleasant. I have before spoken of the excellent action of lemon-juice on the system, at those seasons of the year when fruit is scarce, and fresh vegetables not easy to be obtained. I have no doubt that the addition of lemon-juice to tea would have a most beneficial effect on the health. At the same time, I do not flatter myself that any of you will try it; we are all too much the slaves of inveterate habit to allow reason to exercise any influence over our accustomed practice, and had our grandmothers chosen to add vinegar or pepper to their tea, instead of sugar and milk, we should have adhered to the practice, pitying all those whose tastes or judgment had led them to adopt any other way of drinking their tea.

I have not exhausted my subject, and in the next lecture, when I come to speak of the other beverages of which we partake after infusing in boiling or hot water, shall perhaps have an opportunity of adding a few more words on the subject of tea.

THE practice of taking warm beverages is almost universal amongst mankind. The inhabitants of the tropical forests of Africa, as well as the natives of Lapland and Kamschatka, are equally addicted to the practice of drinking warm infusions. The Egyptians and Jews, the Greeks and the Romans, all partook of heated beverages of some kind or other. Not only are fluids taken heated, but solid food cooked by heat is preferred warm. Long before the introduction of tea and coffee into this country, warmed beverages were popular, and an infusion or decoction called salep was sold hot in the streets of London. It is perhaps worth while, before speaking of coffee and chocolate, to remind you of the nature of this salep. The substance sold in the shops under this name is

procured from the roots of several species of Orchidaceous plants. Some of these are natives of this country, as Orchis Morio, Orchis mascula, and Orchis maculata. They have all large tuberous roots, which yield, on boiling in water, a mucilaginous substance. This is one of the modifications of starch, and is called by chemists bassorin. There is also accompanying this undoubtedly some nutritious matter, which will account for the general use of salep amongst the natives of the East at the present day. When the roots are ready for use they are dug up and dipped in warm water, by which process a fine brown skin which covers them, something like the skin of a potato, is easily removed by means of a coarse cloth or brush; they are next arranged on a tin plate, and heated in an oven for ten minutes, which gives them a semi-transparent or hornlike appearance. They are then withdrawn from the oven, and, after exposure to the air for a few days, they are ready for use. When put into cold water they swell up and form a kind of mucilage. One part of powdered salep in forty-eight parts of boiling water forms a thick mucilaginous liquid. It is this liquid, flavoured with sugar and sassafras chips, that was sold in the streets of London before coffee was introduced. I do not know that it can be procured anywhere now; but I have met with persons who recollect having seen this beverage sold at stalls in the streets of London, as coffee is now. Dr. Percival, a physician in London, wrote a book, as late as 1773, on the preparation, culture, and uses of the orchis-root, in which he refers to the abundance of orchis plants in some parts of this country, and recommends them as an economical

article of diet. I cannot, however, from any experience of my own, speak of the value of the orchis-root in diet. There is one remark I would make, and that is, that the beverages drunk before the introduction of tea and coffee seemed free from any agent capable of acting on the nervous system in the same way as theine. In fact, although the modern warm beverages contain so generally this principle, it would appear that the heat which they contain is, after all, their universal recommendation.

The cause of this preference for heated food is, perhaps, worth a moment's inquiry. It has been observed, where persons have taken cold food for a length of time, that they have become depressed, and their stomach disordered. The fact is, when we take food considerably lower than 98°, the temperature of the human body, it abstracts heat from the stomach and surrounding tissues; and unless the system has the power of manufacturing an additional quantity of heat to supply that which has been lost by raising the temperature of the food, a general depression of the vital powers will take place. We know that persons are sometimes made very ill, and even killed, by taking, in an exhausted state, a draught of cold water or an ice. This is, perhaps, sufficient to indicate the fact, that in taking warm foods and drinks, we are sparing the system the effort of producing a quantity of heat, which can only be done by the destruction of a certain quantity of tissue by the process of oxidation. There is no doubt, that where vigorous oxidation goes on in the body, and a rapid metamorphosis of tissue takes place, there the body will exhibit the greatest amount of power, provided this takes place within the limits of health. But the

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human body may be exposed to too much oxidationthere may be a more rapid combustion of tissue than there are processes of renewal, and under these circumstances the body will suffer. It is on this ground, I believe, that warm food and drinks are found so acceptable to mankind. When the body needs food or drink, it is usually in an exhausted state; and as cold food makes an immediate demand on the system for heat before it can itself supply the materials for combustion, the body is taxed to supply heat at a moment when it is least fitted for it-hence the instinctive preference for warm food. This is much more the case with liquid than with solid food, and as the former contains generally little nutritive or heat-giving matter, it acts all the more injuriously on the system when taken cold.

These facts will explain a great many of the peculiarities of our diet. It shows us why it is that we take our tea and coffee warm at breakfast, after the long abstinence from food during the night. It explains how it is that many persons cannot drink cold water when they first rise in the morning. It throws light on the practice of eating hot soup at the beginning of the principal meal. It accounts for so large a number of teetotallers substituting warm weak tea or coffee at their meals for cold water. It seems to me to be, in fact, the explanation of the universal preference for warm food amongst mankind where it can be procured.

I know there is a contrary taste for taking ices and iced drinks. But this I suspect is more an acquired than a natural taste, and is rather the luxury of the over-fed and the indolent than the instinctive tendency of the race. In fact, ice in this country is only thought