"[P]hlogiston was held to be a material and therefore ponderable substance, so that its escape from a combustible should have caused the latter to diminish in weight; yet the metals and phosphorus were known to increase in weight by combustion. Thus the lameness of the phlogiston hypothesis was betrayed at its first step, and it had to be furnished with a crutch, in the shape of an assumption that it was a principle of levity, so that a body containing it weighed less than if it were absent, before it could move a step further. Many of the Phlogistians... did not adopt this assumption... but they ignored the phenomenon of increased weight... and stood in the anomalous position of professors of a Quantitative Science, who should weigh and measure... and yet had put aside the balance as a useless thing."