SILK-WORMS. 
131 
silk-worms being too closely distributed on the 
hurdles, particularly in the last age. This insect, 
sidered under a new, but not less interesting, aspect. I 
have seen pains, vulgarly called rheumatic, sometimes disap- 
pear without any evacuations, in the course of an hour, 
either by the application of certain remedies, or by friction, 
or by plasters. Can it be said that the pain proceeded 
from too much excitation, and the remedy has allayed it ? or 
that it was want of excitation, and that the remedy has 
given it? Surely not, since other sedative or exciting reme- 
dies failed in producing this effect. This phenomenon then 
depends on a distinct quality in the remedy applied. Either 
the pain arose from a superabundance of a certain impal- 
pable fluid, which appears of the nature of electricity, and 
the remedy, by attracting it, delivered the part affected by 
the pain ; or, the pain arose from a deficiency or diminution 
of this fluid in the organ affected, and the remedy may have 
communicated a portion of the fluid contained within itself, 
and thus have removed the pain. The induction drawn 
from this may be hypothetical, but the facts are certain ; and 
there is no practitioner that may not have observed, that in 
applying, for instance, the plaster of cantharides, or Spanish 
flies, as a rubefacent, upon an affected part, it will make 
the pain cease sometimes in less than aD hour after the ap- 
plication • and prescribing frictions, or embrocation with a pre- 
paration of cantharides, has produced the same phenomenon ; 
as also by dry friction with the brush or flannel. It would be 
desirable to make experiments to ascertain how remedies act 
when put in direct contact with the electrical fluid. I am 
•persuaded, that were this subject to be well investigated, a 
point so entirely new would be very beneficial in medical 
science. I have, in my treatise on small-pox and chicken- 
pox, urged physicians to inquire into it. 
I believe electrical fluid to be one of the necessary ele- 
ments which constitute, and bring into action, the organic 
tissue ; that it is the principal agent in the production of the 
phenomena which- arise from the contact of medical sub- 
G 6 
