His attack on these questions was to produce a much more general theory than had previously been attempted based not on heat as random motion of atoms, as Hooke and Boyle had done, but by the concept of heat as a weightless fluid called caloric.
Kanyang atake sa mga katanungan na ito ay upang makabuo ng isang mas pangkalahatang teorya kaysa sa nagkaroon na dati ay sinubukan na hindi batay sa init tulad ng random na kilos ng mga atom, bilang Hooke at boyle had tapos na, ngunit sa pamamagitan ng konsepto ng init bilang isang timbang tunaw na tinatawag na mainit.