Such as are somewhat yellow, golden, frothy, and thin, indicate only want of concoction, but nothing positively bad. But such as are intensely yellow, golden, frothy, green, viscid, round, and still more the black, are bad. For, with the exception of the blood, whatever of the other humours is unmixed, indicates a bad diathesis, having its origin in an inflammatory heat. The bloody sputa are of an intermediate character, but those of yellow and black bile are unfavorable. The manner in which they are brought up ought also to be considered; for, if they are readily spit up, it is clear that such are good, whereas the contrary are bad. It is an indication of complete concoction that the expectoration is unctuous, white, and equable, and in consistence, neither fluid nor very thick; as it is of a complete failure of concoction that it is not spit up at all. If it is indeed spit up, but thin, it is a mark of feeble concoction. If it is of an unmixed yellow or golden colour, it is not good. But if it is livid, of a verdigris-green, or black, it is a most fatal symptom. * * * * * COMMENTARY. Galen has treated fully of this subject in his work (de Crisibus, ii, 10.) See also Hippocrates (Prognost. and Coacæ), and Celsus (ii, 9.) Aëtius is somewhat fuller than our author (v, 52.) See Avicenna (iv, 2); Averrhoes (Cantic. i, 2); Haly Abbas (Theor. vii and x, 10); Rhases (ad Mansor. x, 24.) We shall be content with giving a few of the observations of the Arabians, of whom Haly is the most full and accurate upon this head. The lungs and the other parts within the chest being the organs of life, when affected, they occasion inflammation of the heart. Expectoration indicates some affection of those parts. When the expectoration is thin and small in quantity, the disease is not concocted; when the sputa are of moderate consistence and equable, the disease is at its acme; when thick, it is certainly on the decline. Thinness indicates that the humour which occasions the complaint is of a subtle nature; thickness, the contrary. Blackness indicates vehement heat. Green sputa are indicative of the presence of green bile, white of phlegm, and redness of blood. When fetid, they proceed from putrefaction. Black sputa indicate great danger. Prosper Alpinus makes many ingenious remarks on the characters of the sputa. (De Vita et Morte ægrot. vii, 19.) SECT. XVI.—THE DIAGNOSIS AND CURE OF EPHEMERAL FEVERS.