that lightning was an electrical discharge. The sagacity of Franklin's
scientific inquiries is well illustrated by his notes on colds and their
causes. He maintains that influenzas usually classed as colds do not
arise, as a rule, from either cold or dampness. He points out that
savages and sailors, who are often wet, do not catch cold, and that the
disease called a cold is not taken by swimming. He maintains that people
who live in the forest, in open barns, or with open windows, do not
catch cold, and that the disease called a cold is generally caused by
impure air, lack of exercise, or overeating. He comes to the conclusion
that influenzas and colds are contagious--a doctrine which, a century
and a half later, was proved, through the advance of bacteriological
science, to be sound. The following sentence exhibits remarkable
insight, considering the state of medical art at that time: "I have long
been satisfied from observation, that besides the general colds now
termed influenzas (which may possibly spread by contagion, as well as by
a particular quality of the air), people often catch cold from one
another when shut up together in close rooms and coaches, and when
sitting near and conversing so as to breathe in each other's
transpiration; the disorder being in a certain state." In the light of
present knowledge what a cautious and exact statement is that!

There being no learned society in all America at the time, Franklin's
scientific experiments were almost all recorded in letters written to
interested friends; and he was never in any haste to write these
letters. He never took a patent on any of his inventions, and made no
effort either to get a profit from them, or to establish any sort of
intellectual proprietorship in his experiments and speculations. One of
his English correspondents, Mr. Collinson, published in 1751 a number of
Franklin's letters to him in a pamphlet called "New Experiments and
Observations in Electricity made at Philadelphia in America." This