( 641 ) 
madet), I have tried to find further data about the effect on the 
respiration of the excitation of some periferie nerves. I have 
to return thanks to Mr. van CALCAR and Mr. H. JaGer for 
their valuable assistance. Since the impulse to this investigation 
which MARSHALL Hatv’s “Treatise of the Nervous System” gave 
in 1840, many experiments have been made on this subject, but 
on the whole the results do not agree very well. The difference of 
animals experimented on, of the conditions under which the expe- 
riment was made, of the nature of the excitation used, is so difficult 
to bring under simple points of view, that I thought it desirable 
to make a new attempt under conditions as much the same as possible. 
For want of time I could make only a beginning with this very 
interesting study of the automatism of respiration, the knowledge 
of which is of the highest importance both from a physiological and 
a clinical point of view. Nevertheless it seems to me, specially with 
a view to LABORDE’s opinion, that I am justified in communicating 
some of the obtained results. 
The animals experimented on were dogs, almost all of the same 
species. The experiments were made in narcosis of pure chloroform. 
In the beginning this gave difficulties as it is a well-known fact, 
that dogs which are not morphinized, react very violently on the 
inhalation of chloroformvapours and therefore often succumb of the 
narcosis. . 
On purpose I did not make use of the mixed morphia-chloroform 
narcosis, because morphia introduces a factor, by no means to 
be neglected in the mechanism of respiration (as proved by 
the well-known morphia-sigh) which indicates over-irritability of 
inspiration-centres. 
The chloroform also introduces an unknown factor, but this seemed 
to me a peremptory demand of humanity. Moreover if dogs are not 
narcotized there is also an unknown factor acting, because pain 
makes the respiration strongly irregular. When the narcosis with 
pure chloroform has become complete, it gives a fine regular 
respiration, which changes as long as active stimulation lasts, but 
generally returns immediately to the normal condition. 
The explanation of the violent reaction, which takes place in the 
beginning of narcosis, is not found, as we should be inclined to 
assume, in the disagreeable irritating action of the chloroform on 
1) Proc. Roy. Acad. Amsterdam Oct. 29, 1898 and March 25, 1899. Dr. WrarDt 
Beckman. Diss. Inaug. 1899. Amsterdam, De invloed van de schors der voorhoofds- 
hersenen op de ademhaling. 
