494 PHYSIOLOGY CHAP. 



periodic respiration in man or other animals. Flourens (1842) 

 accidentally observed periodic respiration in an animal on which, 

 after extirpating the brain, the two vagi had been divided. M. 

 Schiff (1859) described the same phenomenon in mammals after 

 copious haemorrhage and pressure exerted upon the medulla 

 oblongata. 



Traube (1871) induced periodic respiration in cases of heart 



FIG. 231. Periodic respiration observed on U. Mosso during sleep, 4/>60 metres. 



disease by hypodermic injection of morphia, and increased it by 

 the same means in patients who already exhibited the phenomenon. 



In 1874 we obtained the same effect in dogs, by giving them 

 intravenous injections of laudanum and subsequent artificial 

 respiration sufficient to produce apnoea (Fig. 232). 



Filehne and Heidenhain (1874) simultaneously obtained it in 

 dogs and rabbits with intravenous injections of chloral hydrate. 



FIG. 232. Periodic respiration in dog anaesthetised by intravenous injection of 5 c.c. laudanum. 

 Tracheotomy was performed after previous production of apnoea by artificial respiration with- 

 the bellows. (Luciani.) The tracing was obtained by connecting the tracheal tube with a 

 receiver containing 30 litres of air, .joined to a writing tambour. 



Cuffer (1878), who had noticed the frequent coincidence of the 

 respiratory phenomenon with interstitial nephritis, succeeded in 

 provoking it in dogs by intravenous injections of creatine and 

 ammonium carbonate. Smirow (1884) obtained it in dogs with 

 inhalations of sulphuretted hydrogen ; Langendorff (1881) with 

 injections of niuscarine and digitaline ; Bordoni (1886) with 

 injections of scillaine and gelsemine, on frogs and toads. 



x\fter discovering the cardiac phenomenon in the frog (1872- 

 1873, in Lud wig's laboratory) we attacked the experimental study 



