Without going into further details, it is readily seen that the teachings of Joseph Smith, in 1833, in relation to the value of tea and coffee in human drinks, harmonizes with the knowledge of today. Moreover, he was in advance, in the certainty of his expressions, of the scientists of his day. It is true that caffein had been found in coffee and tea a few years before the revelation of 1833, but the physiological action of the drug was not known until many years afterwards. Besides, as in the case of tobacco, the Church leaders in speaking against the use of tea and coffee did not mention the poisonous principle that had recently been discovered in them; thus revealing their ignorance of the matter. [Sidenote: The doctrines regarding the values of herbs and fruits harmonize with recent scientific truths.] "And again, * * * all wholesome herbs God hath ordained for the constitution, nature, and use of man. Every herb in the season thereof, and every fruit in the season thereof; all these to be used with prudence and thanksgiving."[A] [Footnote A: Doctrine and Covenants 89:10, 11.] This doctrine, which seems self-evident now, also evidences the divine inspiration of the Prophet Joseph. At the time this revelation was given, food chemistry was not understood; and, in fact, it was not until about 1860, that the basis upon which rests our knowledge of food chemistry, was firmly established. We now know that every plant contains four great classes of compounds: mineral substances, fats, sugars and starches, and protein, or the flesh-forming elements. We further know that no plant can live and grow without containing these groups of nutrients. It is also well understood that these substances are necessary for the food of the animal body, and that animal tissues are, themselves, composed of these groups, though in different proportions. In short, it has long been an established fact of science that any plant that does not contain a poisonous principle, may by proper cooking be used as a food for man. When Joseph Smith wrote, this was a daring suggestion to make, for there was absolutely no fact aside from popular experience, upon which to base the conclusion. The qualifying phrase, "all wholesome herbs," undoubtedly refers to the existence of classes of plants like coffee, tea, tobacco, etc., which contain some special principle injurious to the health. [Sidenote: The doctrine concerning the use of meats is scientific.] "Yea, flesh also of beasts and of the fowls of the air, I, the Lord, have ordained for the use of man with thanksgiving; nevertheless they are to be used sparingly; and it is pleasing unto me that they should not be used only in times of winter, or of cold, or of famine."[A] [Footnote A: Doctrine and Covenants, 89:12, 13.]