378 OF RESPIRATION. 



the respiratory movements can be arrested in several ways by nervous influ- 

 ence. Thus it appears that this can be effected (1), by irritation of the 

 pneumogastric nerve (Traube), (2), by irritation of the larynx (Bernard, 

 Burkart), and (3), by irritation of the nostrils nasal branch of the infra- 

 orbital (Schiff and Kratschmer). 1 Slight irritation of any sensory nerve 

 augments the number of the respiratory movements (Schiff). Strong irri- 

 tation diminishes (Mantegazza) or altogether arrests them, especially if the 

 excitant he heat, when inspiration-tetanus is produced (Schiff). According 

 to M. Bert 2 the arrest in the above instances may take place either in expi- 

 ration or inspiration, though it is more easily produced in expiration ; coin- 

 cideutly with the arrest of the movements of respiration the general move- 

 ments of the animal are arrested it remains perfectly motionless. 



298. The importance of moderate excitation of the general sensory nerves 

 of the surface, and especially of the fifth pair, in exciting the respiratory 

 movement, is easily shown. Thus Pfliiger 3 observed that, on opening the 

 abdomen and uterus of a pregnant rabbit at the full time, the foetuses were 

 brought into view enveloped in the membranes, and quiescent. Ou detach- 

 ing the placenta a few feeble iuspiratory movements occurred, especially 

 when the animals were pinched ; but death soon took place. When, how- 

 ever, the membranes were laid open, lively inspiratory movements followed, 

 which soon became rhythmical. In the same way it has long been a well- 

 known fact, that the first inspiratory effort of the new-born infant is most 

 vigorously performed when the cool external air comes in contact with the 

 face ; and that impressions on the general surface, such as a slap of the 

 hand on the nates, are often effectual in exciting the first iuspiratory move- 

 ments, when they would not otherwise commence. Dr. M. Hall relates an 

 interesting case, in which the first inspiration was delayed, simply because 

 the face was protected by the bed-clothes from the atmosphere; 4 and, on 

 lifting up these, the infant immediately breathed. Dr M. Hall has also 

 mentioned the important fact, that although, if the cerebrum be removed, 

 and the pneumogastrics be divided, in a young kitten, the number of acts 

 of respiration will be reduced to four in a minute, yet by directing a stream 

 of air on the animal, or by irritating various parts of the general surface, 

 we may excite twenty or thirty acts of respiration within the same space of 

 time. He further remarks that in the very young warm-blooded animal, as 

 in the cold blooded animal, the phenomena of the excito-motor power are 

 far more vividly manifested than in the older and warm-blooded. In the 

 very young kitten, even when asphyxiated to insensibility, every touch, con- 

 tact, or slight blow, every jar of the table, any sudden impression of the ex- 

 ternal air, or that of a few drops of cold water, induces at once energetic 

 reflex movements and acts of inspiration. This may be looked upon as 

 Nature's provision for the first establishment of the respiratory function in 

 the new-born animal. But the influence of the nerves of the general sys- 

 tem is by no means wanting in the adult; as many familiar facts demon- 

 strate. 'Thus every one knows that the first plunge into cold water, or the 

 first descent of the streams of the shower-bath, or even the dashing of a 

 glass of cold water in the face, will produce inspiratory efforts; and this 

 fact has many important practical applications. Thus in the treatment of 

 Asphyxia, whether congenital or the result of narcotic poisoning, drowning, 

 etc., the alternate application of cold and heat is found to be one of the 

 most efficacious means of restoring the respiratory movements; and a par- 



1 Sitz d. k. Akad. zu VVien, 1870, Bd. Ixii, p. 



2 Bmwn Sequard, Ar-chives do Physiologic, t. ii, pp. 179 and 322. 

 s Pfln-<T's Ardiiv, 18(i8, p. 01. 



4 Nf\v Memoir on the True Spinal Marrow, etc., p. 29. 



