Treatise on Poisons by Sir Robert Christison

5. Another criterion relates to the progress of the symptoms. The

symptoms of narcotic poisoning advance for the most part gradually: but those of apoplexy in general begin abruptly. Sometimes apoplexy commences at once with deep sopor. Narcotic poisoning never begins in that way, except in the instances of hydrocyanic acid and the narcotic gases; the sopor is at first imperfect, and it increases gradually, though sometimes very rapidly. Apoplexy, however, does not always begin with deep sopor; occasionally the sopor begins and increases like that of narcotism.