THEIR NATUBE AND EFFECTS. 35 



be observed in tbe greater excursus of the rcovement; 

 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 per- 

 ceptible 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 acce- 

 leration 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 tiie 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 retard- 

 ation, and the accompanying diminution of excursus are 

 well shown ; but tbe nature of the convulsive movements 

 at the ^nd 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, 



3 * 



