Thus the coldness, shivering, and consequent heat, which constitute the first attack of fever, are very plausibly explained; but in the mode of cure this learned physician fell into the same mistake with Dr. Boerhaave; for though spasm is undoubtedly, even according to himself, an _effect_, he directs his medicines entirely against it, as if it were a _cause_. Thus, forgetting what he had just before advanced, that the spasm is occasioned by debility, he recommended the most debilitating medicines and regimen to cure people already too much debilitated; and to such practice his enemies alledged that many fell victims. The theory and practice, however, still kept its ground; and as great numbers of students were every year bred up in the belief of it at Edinburgh College, who carried the principles of their teacher to all parts of the world, it bade fair for becoming universal. But, in the midst of this eclat, the whole system received such a rude shock from the doctrines of _John Brown_, though at that time not even M. D. as it hath not yet recovered. Though the author of the new system contended, as much as Dr. Cullen, for the supremacy of the nerves, he did not upon that foundation attempt to establish his practice. He considered the living body as one machine, the _whole_ of which might be acted upon, and always was acted upon by certain powers. It possesses a certain inexplicable property called _excitability_, capable of being augmented or diminished. Every power which augments the _excitability_ he called a _stimulus_; the opposite would have been a _sedative_; but according to this system there is not any sedative, nor can there be one in nature. The reason is, that excitability itself has no existence but in consequence of the action of certain powers called _stimulants_. The total subduction of these reduces the excitability to nothing; of consequence no power can act against it in a state of non-existence. What other physicians call _sedatives_, therefore, according to the new system, are only weak _stimulants_. The fallacy of such reasoning is obvious; but as it does not affect the practice, we shall not spend any time in considering it further.