THEIR NATURE AND EFFECTS.
be observed in the greater excursus of the movement; probably due to carbonic acid stimulation, but the sadden and jerky character is unabated. In No. VII. the respiratory movement is reduced to a barely perceptible movement of the chest walls, completely incapable of effiecting respiration. No. VIII. shows even this movement absent; but at the end of the tracing, the commencement of the convulsions that terminate life is marked. Chart No. II presents some contrasts of interest. It gives nearly the whole course of the respiratory movements of a fowl, from the moment of the injection of the poison till the occurrence of death, in a case in which a large amount of cobra-poison was given, causing death very rapidly. From it will be seen how very much more pronounced the acceleration is when a large quantity of poison is given, and that when the stage of acceleration is passed the excursus is lessened quite as rapidly as the frequency. The respirations before the administration of the poison bear to the respirations at their greatest degree of acceleration, in the tracing IV., the ratio of lour to seven. Chart No. III. is a series of tracings from a large pariah dog, the acceleration followed by retardation, and the accompanying diminution of excursus are well shown; but the nature of the convulsive movements at the end are of great interest. They begin by regular contractions of the respiratory muscles; in the period of their gseatest violence they lose all respiratory character,
