LECTURES

ON THE

MATERIA MEDICA, 1761.

A Know ledge of the Materia Medica comprehendsa knowledge of all the Subftances or Preparationsemployed in Diet or Medicine : Different authorshave «mployed different methods in delivering the know-ledge 01 this Science, all of them liable toobje&ion, need-lefs here be pointed out. I fhall here (hew you the planwhich I iifend to follow; fo that, if you once be convin-ced of its propriety, you will eafily fee the errors of others.Every fubjeft vill be confidered under four different heads.

ift, Its knowV(jg e) or the method of diftinguifhing it.

2d, Its virtues'r[ diet or in medicine.

3d, '1 he foundathn of thofe virtues in the fcnfiblc qua-lities, or its comical properties.

4th, Its particular application to medicine, or its phar-imaceutical treatment.

1 ft. The knowledge, oj t'r^ fubjefl is of two kinds, naturaland artificial; the firjl procurable alone by the too muchneglected iludy of Natural 4iilory ; the lajl, by frequentintpe&ion, or handling of thef u bje£t. 2dly. The virtuesihall be delivered, full, accorditnr to the feveral general in-dications, and then as particulary applicable to differentdifeafes. The Materia Medica ha^ received infinite difad-vantages from the various Signatulfts, Aftrologers, andChemifts. Experience itfelf is liable to fo many eriors ofignorant or deceitful men, and fo many virtues have beentaken upon trull from different authors, thut I expeft to bepardoned if I fhall not give too much credit 10 the affertionof others, and rather chule pauca fcire quam tnulta opinari.Colour, of all methods of knowing the virtues of fubje£tsa priori, is the moft uncertain; Smell extends a little farther;

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