of pleasing the palate, let me recommend the profound study of the properties of a lemon.

It is a descent to speak of the other acids. Tartaric acid is found in the juice of the grape, and I have already spoken of its properties when telling you about wine. Like citric acid, it may be separated in the form of crystals, and when powdered, being cheaper than citric acid, it is used for making effervescing powders.

Malic acid is found in apples and pears, and gives the acidity to those fruits, and the wines made from them known under the name of cyder and perry. The poisonous oxalic acid is the flavouring ingredient that recommends sorrel (Rumex acetosa) and the wood-sorrel (Oxalis acetosella) as salad, and the leaf-stalks of rhubarb as a substitute for gooseberries and currants in the early season of the year.

All these acids, like oxalic acid, are poisonous in large doses, but we may learn from their beneficial action on the system, that many of these substances which, when taken in excess, destroy the system, may be taken in small quantities, not only with impunity, but with advantage.

But I must close this long lecture on matters of taste. I fear I have wearied you, but if I have impressed you with the importance of this subject, I shall have succeeded in my object, and I hope convinced you that Mr. Brooks gave a great practical hint to our cooks and housewives when he knowingly ejaculated, "It's the seasonin' as does it."

ON TEA AND COFFEE.

IN these lectures, you may regard me as acting the part of your host. I began by giving you a cup of cold water, than which nothing is more provocative of appetite. I then placed before you the salt-cellar with its contents, and the various forms of plants we eat as salads, and popularly known as purifiers of the blood. Aware, however, that you could not be sustained on this diet, I introduced you to starch and sugar, and the philosophy of making puddings and eating sweetmeats. These, I explained to you, were heat-giving materials, but inferior even in that function to butter, fats, and oils. I then placed before you bread and meat, poultry, fish, and game, not denying you a glass of ale or wine, to stimulate your digestion, and give a relish to your food. In the present and succeeding lecture we will,

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if you please, repair to the drawing-room, and discuss the merits of tea, coffee, and chocolate, previous to taking a pipe of tobacco with the American Indian, and a dose of opium with the Chinese.

Tea, coffee, and chocolate belong to the same class of foods as alcohol and the volatile oils. The constituents they contain act on the nervous system, but they act in a different way. Alcohol and the condiments and spices, discussed in the last lecture, are stimulants of the nervous system; but tea and coffee are sedatives. The one is capable of destroying life by producing excessive action; the other destroys life by preventing action.

The way in which these substances act on the nervous system is still a mystery. One thing seems to be ascertained, and that is, that the active agent, whether we call it a food, a medicine, or a poison, must be brought in contact with the nervous matter on which it acts. Alcohol, on being brought in contact with a nerve, excites it to action; tea, on being brought in contact with the same nerve, calms and subdues its activity. Hence, alcohol and tea are natural antagonists. Physiologically antagonists in their action on the human nerves, they have been commercially and dietetically antagonists from the time the latter became known amongst the European nations.

The nations of antiquity - the Egyptians, Jews, Greeks, and Romans-knew nothing of tea. They all regarded alcohol as one of the most precious luxuries of food, and were no strangers to its seductions and destructive influences. The temptations of this powerful agent, and the want of a less stimulating and yet not

less agreeable beverage, was one of the defects of their civilization. We miss from the sculptures of Nineveh, the paintings of Egypt, the statuary of Greece, and the furniture of Pompeii, those vessels which we have borrowed from the Chinese, and which are so characteristic of our civilization.

The strong spirituous draughts of the Celt, the Saxon, and the Norse, were inhaled from the polished skulls of slaughtered foemen; the sparkling and highlytinted wines of the Mediterranean races were poured out of gold and silver tazzas and amphoras; or they stimulated appetite by shining through the transparent sides of crystal cups. These ostentatious utensils were unsuited to the modest character of tea or coffee; and China, which has the merit of supplying the civilized world with the finest of these invigorating infusions, has also presented us with appropriate vessels to contain it, with implements excelling in beauty and refinement anything of this kind that the world had before produced.

The Majolica ware of Southern Europe, though covered with a fine and durable glaze, and decorated with designs painted by the scholars of Giotto, Pietro Perugino, and Raphael, was disregarded when the novel and exquisite porcelain imported from China became known. The pure white body of this earthenware, formed of the yet unknown kaolin and petuntze, had a charm which, though unaided with artistic adjuncts, bore down all competition. The unpretending brown and semi-turbid "infusion of tea," held in these elegant cyathides and cylices, or cups and saucers, diffusing around its delicate aroma, soon sur

passed, in the favour of the cultivated classes, the more exciting and showy freight of the sculptured bowl. For a time tea was sipped out of minute cups of eggshell porcelain by aristocratic lips only, and amongst elegant social groups, that would have satisfied the fastidious fancy of Watteau; but soon the fashion of tea-drinking descended to the lowest ranks, so that even in the time of Dr. Johnson, he was able to say, "no washerwoman sat down to her evening meal without tea from the East Indies, and sugar from the West."

Tea, coffee, and chocolate were unknown as articles of diet in Europe previous to the seventeenth century. The consumption of tea in the United Kingdom alone at the present time is 80,000,000 pounds annually; of coffee we consume 40,000,000 pounds; and of cocoa, 4,000,000 pounds in the year, making altogether about four pounds every year for each man, woman, and child in the country.

It is very natural that we should turn to the composition of these three things, and ask if there be anything they contain in common which can explain their action on the system, and the influence they have gained over the appetites of mankind? Have they, like wines, spirits, and beers, an active agent, which in each case is the basis of its actions and influence? The parts of these plants employed in diet are various. We obtain tea from the leaves of the plant, coffee from the roasted berries, and cocoa from the pounded seeds. Nor are their general properties less varied. Tea contains volatile oils and tannin; coffee contains empyreumatic oils and caffeic acid: whilst cocoa contains fifty