have been lately sent to Africa.  History will never relate the horrors committed by the British army, in the southern States of America.  They raged in Virginia six months only, from the middle of April to the middle of October, 1781, when they were all taken prisoners; and I give you a faithful specimen of their transactions for ten days of that time, and on one spot only. Ex pede Herculem.  I suppose their whole devastations during those six months, amounted to about three millions sterling.  The copiousness of this subject has only left me space to assure you of the sentiments of esteem and respect, with which I am, Sir, your most obedient, humble servant,

Th:  Jefferson.

LETTER CXLV.—­TO JAMES MADISON, July 19, 1788

TO JAMES MADISON, of William and Mary College.

Paris, July 19, 1788.

Dear Sir,

My last letter to you was of the 13th of August last.  As you seem willing to accept of the crumbs of science on which we are subsisting here, it is with pleasure I continue to hand them on to you, in proportion as they are dealt out.  Herschel’s volcano in the moon you have doubtless heard of, and placed among the other vagaries of a head, which seems not organized for sound induction.  The wildness of the theories hitherto proposed by him, on his own discoveries, seems to authorize us to consider his merit as that of a good optician only.  You know also, that Doctor Ingenhouse had discovered, as he supposed from experiment, that vegetation might be promoted by occasioning streams of the electrical fluid to pass through a plant, and that other physicians had received and confirmed this theory.  He now, however, retracts it, and finds by more decisive experiments, that the electrical fluid can neither forward nor retard vegetation.  Uncorrected still of the rage of drawing general conclusions from partial and equivocal observations, he hazards the opinion that light promotes vegetation.  I have heretofore supposed from observation, that light affects the color of living bodies, whether vegetable or animal; but that either the one or the other receives nutriment from that fluid, must be permitted to be doubted of, till better confirmed by observation.  It is always better to have no ideas, than false ones; to believe nothing, than to believe what is wrong.  In my mind, theories are more easily demolished than rebuilt.

An Abbe here, has shaken, if not destroyed, the theory of De Dominis, Descartes and Newton, for explaining the phenomenon of the rainbow.  According to that theory, you know, a cone of rays issuing from the sun, and falling on a cloud in the opposite part of the heavens, is reflected back in the form of a smaller cone, the apex of which is the eye of the observer:  so that the eye of the observer must be in the axis of both cones, and equally distant from every part of the bow.  But he observes, that he has repeatedly