Nor grants the passive fluids power to kill;
A learned friend some subtler reason brings,
Absolves the channels, but condemns their springs;
The subtile nerves, that shun the doctor’s eye,
Escape no more his subtler theory;
The vital heat, that warms the labouring heart,
Lends a fair system to these sons of art;
The vital air, a pure and subtile stream,
Serves a foundation for an airy scheme,
Assists the doctor, and supports his dream.