602 REPORT—1899. 
from electrodes produced a diminution in the steepness of curve, and 
it is believed an alteration of its character. 
The value of this latter observation is enhanced by the manner in 
which other changes unrelated to changes of blood pressure, but known 
from further research to occur in nerve during conditions of experiment, 
are swamped by the superposition of artery, it being presumed that value 
of derived circuit through galvanometer is rendered comparatively negli- 
gible by its relatively large resistance. 
In cases of all previous part of research it may be said that the phy- 
siological continuity of tissue examined is essential. 
Summing up, it may be said that all the experiments upon which 
statements have been based were carried out under the conditions of 
original experiments upon phrenic nerves ; that is, that the experimental 
method used for obtaining the alterations of blood pressure! consisted of 
curarisation, artificial respiration, and intervals of its suspension. 
This, though not a good method for the unravelling of secondary 
problems which have presented themselves, allows one to translate all the 
occurrences which have been found in other nerves and tissues to a pro- 
bable occurrence during any one of phrenic experiments. The main results 
may be tabulated as follows :— 
(1) Current changes have been found in divided nerves directly pro- 
portional to changes of pressure, the reiation between the two being 
however, as to time and quantity of a gross kind. 
(2) Current changes have been found in peripheral end of divided 
vagus nerve inversely proportional to changes of blood pressure, in which 
relation is much more exact. 
(3) The latter class of changes has not been obtained from any other 
nerve examined ; 
(4) but is constantly to be obtained from the divided carotid artery, 
though here less exact ; , 
(5) and with great exactness and magnitude from vagus carotid pre- 
paration. 
(6) That this latter result is diminished by ligature of vagus below 
point examined. 
Having thus obtained information of events met with in other tissues, 
nerves, and blood-vessels, situated in near neighbourhood and obtaining 
their blood supply from very similar sources, experiments were resumed 
upon phrenic itself. 
Simultaneous curves of electrical changes in phrenic and of general 
blood pressure show no correspondence of a kind to explain the charac- 
teristic phenomena obtained in phrenic nerve alone of all the nerves 
examined, and the large alterations of blood pressure which occur in every 
experiment cannot be even definitely said to constantly affect the base line 
of phrenic tracing. 
Te make the result more conclusive, simultaneous records were 
taken both of current changes in phrenic and in vagus carotid preparation, 
which latter is known to repeat all the incidents of a blood-pressure 
curve. 
The tracings obtained show the typical appearances of either. curve, of 
quite diverse types, showing no relation of the kind sought for. Oscilla- 
1 Chloroform anesthesia was used, 
