When our assent is demanded, on the credibility of the relator, to any fact which we are not permitted to examine, we can only judge of its probability from his known accuracy and ability. Several specimens of these have occurred in the course of our enquiry. Quotations have been misrepresented[87]. Authorities misapplied[88]. Evidence produced which establishes facts, directly opposite to those in support of which it is perverted[89]. Palpable contradictions have been pointed out[90]; and an air of mystery and devotion detected, the tendency of which, when joined to a train of suspicious circumstances, cannot be mistaken[91]. But the inaccuracy betrayed in the directions given with the powder, is sufficient to put us on our guard. _The best general and plain direction_, we are told, _is to repeat half a paper, or ten grains and a half of the powder once in six hours[92], but in South America they seldom give less than twenty_, which the Inventor _thinks right_[93], yet when it fell under the direction of the navy-surgeons, the general rule which was avowedly intended, and is still continued, for the common people, was found to be fraught with danger, and the Inventor admits that it has been necessary to reduce the dose so low as two or three grains[94], thereby acknowledging _the best plain general direction, to be a very improper one for the common people_, since no good reason can be assigned, why ten or twenty-one grains should be given by those who have no medical skill, though it is judged necessary to warn others, who may be supposed capable of conducting its operation, and detecting and counteracting its pernicious effects, of the necessity of reducing it, in some cases, to two or three grains. The only solution of this parodox, is, _there is one faith for the learned, and another for the unlearned_.