The experiments and observations hitherto related render it evident, that Tea possesses a fragrant volatile principle, which in general tends to relax and enfeeble the system of delicate persons, particularly when it is drank hot, and in large quantities. I have known many of this frame of constitution, who have been persuaded, on account of their health, to deny themselves this fashionable infusion, and received great benefit (Sect.VII.). Others, who have found their health impaired by this indulgence, are unhappily induced to continue it for want of an agreeable substitute, especially for breakfast.
But, if such cannot wholly omit this favourite regale, they may certainly take it with more safety, by boiling the Tea a few minutes, in order to dissipate this fragrant principle (Sect.II. 1, andExp.IV.) which is the most noxious; and extract the bitter, astringent, and most stomachic part (Sect.II. 2, andExp.III.) instead of preparing it in the usual manner by infusion.
An eminent physician in the city, frequently experiencing the prejudicial effects of Tea by drinking it in the usual form, was induced, from reading a dissertation upon this subject, published some time since at Leyden[93], to try the infusion preparedafter another manner. He ordered the Tea to be infused in hot water, which after a few hours he caused to be poured off, stand over night, and to be made warm again in the morning for breakfast. By this means, he assures me, he can take, without inconvenience, near double the quantity of Tea, which formerly, when prepared in the usual method, produced many disagreeable nervous complaints.
The same end is obtained by substituting the extract of Tea (Sect.II. 2.) instead of the leaves. It may be used in the form of Tea, by dissolving it in warm water; and, as the fragrancy of the Tea is in this case dissipated, the nervous relaxing effects, which follow the drinking it in the usual manner, would be in great measure avoided. This extract has been imported into Europe from China, in flat round dark-coloured cakes, not exceeding a quarter of an ounce each in weight, ten grains of which, dissolved in a sufficient quantity of water, might suffice one person for breakfast. It might also be made here without much expence or trouble (SeeSect.II. 2.).
It is remarkable, that in all the forms which Du Halde relates, for administering Tea as a stomachic medicine among the Chinese, it is ordered to be boiled for some time, or prepared in such a manner, as to cause a dissipation of its fragrant perishable flavour; which practice, as it seems consonant to experiments here (Sect.II.Exp.III.), may probably have taken its rise in China, from long experience and repeated facts.