As age advances nerve-tissue is less elastic, firmer, less yielding, not so pliable, does not so readily adapt itself to heat modifications. Fever may be the result of traumatism of poisons. Nerves excited cause hyperthermia. Rheumatism may be from trauma or poison. The pulse in scarlatina is more rapid, in typhoid fever slower.
Some poisons excite, while others depress.
In scarlatina the poison excites, in typhoid it depresses. This difference is owing to the nature of the poison ingested, injected or inhaled. Delafield and Pruden in their work on pathology state, Inflammation is a modification of physiological processes. They should have said, inflammation modifies physiological processes and the general temperature of the body. Fever is destructive, not conservative.