very stage of
society, and at almost every period of life; it cannot, therefore, be
much a matter of astonishment, that, from the earliest ages of the
world, persons have been found, who, more idle and more ingenious than
others, have availed themselves of this propensity, to obtain an easy
livelihood by levying contributions on the curiosity of the public.
Whether this taste is to be considered as a proof of the weakness of our
judgment, or of innate inquisitiveness, which stimulates us to enlarge
the sphere of our knowledge, must be left to the decision of
metaphysicians; it is sufficient for our present purpose to know that it
gave rise to a numerous class of impostors in the shape of quacks,
mountebanks, poison-swallowers, fire-eaters, and pill-mongers.

There is another class of adepts, such as sleight of hand performers,
slack rope dancers, teachers of animals to perform extraordinary tricks;
in short, those persons who delude the senses, and practise harmless
deceptions on spectators, included under the common appellation of
jugglers. If these arts served no other purpose than that of mere
amusement, they yet merit a certain degree of encouragement, as
affording at once a cheap and innocent diversion; jugglers of this class
frequently exhibit instructive experiments in natural philosophy,
chemistry, and mechanics: thus the solar microscope was invented from an
instrument to reflect shadows, with which a savoyard amused a German
populace; and the celebrated Sir Richard Arkwright is said to have
conceived the idea of the spinning machines, which have so largely
contributed to the prosperity of the cotton manufactories in this
country, from a toy which he purchased for his child from an itinerant
showman. These deceptions have, besides, acted as an agreeable and most
powerful antidote to superstition, and to that popular belief in
miracles, conjuration, sorcery, and witchcraft, which preyed upon the
minds of our ancestors; and the effects of shadows, electricity,
mirrors, and the magnet, once formidable instruments in the hands of
interested persons, for keeping the vulgar in awe, have been stripped of
their terrors, and are no longer frightful in their most terrific forms.

ON THE TRANSFUSION OP BLOOD FROM ONE ANIMAL TO ANOTHER.

At a time when the shortness of human life was imputed to a distempered
state of the blood; when all diseases were ascribed to this cause,
without attending to the whole of what relate