lijG 



F i; \ i: u 



LXI-KKIMKNT lO'J. 

 A Uog. The medulla cut; pnt-umoguhlrio Kevercd; ttrlificiiil respiration cuiployed ; woorori 

 ndiniuiblcrcd ; carotid urtcry and ociatic iicrvc used. 



Tim*. A«Tt: ue. Iuihtatios. HEMAUKS. 



U. Sm. |^. 



M 



10 50 (iBlvatiic. Strong Faradic current. 



1.1 75 



IJ BO 



16 98 



20 103 



23 113 



26 120 Nrcillo of mnnotnftor now rose fthovo the lop of the re|ri*- 



teriiig druni.aiKl the prt-ssurc couKI no longer be fullowetl. 

 Plate V. Fig. 1, r«'pre«'nl8 the troring of the Brtcri*! 

 pr<'s.siirc of tlii8 experiinrnt, -}- corre.spoMiling t«> iK'giniiing 

 of irritutiun at 10 seconds, -{- 4" ''^ ceijsation of irritatiuo. 

 4:20 p. M. — The splanclniiis divided. 



TiVK, Abtkkial VHUwrRK. luBiTATinx. Rtl-MARK-S. 



M. Src (Mllllmrlrci.) 



3") I'rcssnrc ha.s l)cen steady for some minutes. 



10 3.'> licgan. Strong l-'uradic current. 



13 ta 



1". -If. 



49 



.... 5i 



3C .17 Plate V. Fig. 2, repregents the tracing of this experimcDt, 



-f-curnsponding to Iteginningof irritation at 10 second*, 

 -j--)- to its cciiiiation at 44 sccoo 



I i 43 Ceased. 



'I 37 



3."> 



1 35 Asphyxia produced. 



1:5 44 



1'.8 4S After this the prcissnre did not rise any more. 



Aulnpni/. — The splnnchiiies <'iil below the ln.«t ril).«, just n.s they arc enterin<^ the dinphrngni. The 

 mediillix 1 ..Mii.li.tcly se|)aratcd frmu the pous; only one pucuuiogastric severed in the neck. 



This txjurimrnt certainly sliows that, n/lcr scj>nra(lon of the incdnJla from the 

 jtoiiA ami ti/lrr ficcfion itf the f>phiivlin'ir», the nrtrrinl p)-('i>.'i}irr utill n'*'*, trhm 

 4ttij,hi/ria orrurs or a scnititire nerve in irritntcd: a comparison of tliis rise with that 

 which occurs when tlio sphinchnics only are divided will show that it is as great as 

 the latter. It must therefore be allowed that there is no vaso-motor centre above 

 that of the medulla, which is able to impress the arterial pressure even when the 

 splanchuics arc divided and the dominating power of the abdominal circulation 

 withdrawn. I have also made a series of experiments upon venous pressure, 

 hoping to be able to determine in this way the effect of injuries of the nerve 

 centres upon the blood supidy of nuiseles. No ti-rhniral ditfirtdtit^s of nuirh 

 importance were met with, the iiroiiciicss to blood coagulation being overcome by 

 the use of a mtiinilnl solution of carbonate of .sodiuiu; but it was found that the 

 local conditions of the arteries of a part affect very little the venous pressure, the 

 latter being dominated by the general venous pressure and by the musctdar con- 

 dition of the part timler study : thus in a number of experiments, section of ll>c 



