ON METABOLISM OF THE TISSUES. 235 
accdmpanied by an increased consumption of oxygen, have been confirmed 
except in one casé, when the arterial pressure, and consequently the blood- 
flow through the gland, was greatly reduced. In this case the blood in 
the pancreatic vein was extremely venous, but not entirely deoxidised. 
The question is therefore raised whether the blood gives up its last traces 
of oxygen to the tissues as readily as it gives the rest ? 
The Submanillary Gland.—Researches have been performed with the 
object of discovering the exact influence of the cervical sympathetic nerve 
upon the gland. The following facts have been ascertained ;— 
(1) That stimulation of the cervical sympathetic causes no increase of 
oxygen taken up by the gland. 
(2) That stimulation of the cervical sympathetic causes no water to be 
taken from the blood except as an after effect. 
(3) That stimulation of the cervical sympathetic leads to a diminished 
output of CO, from the gland to the blood, and sometimes even to a 
slight transference of CO, from the blood to the gland. 
(4) That when the cervical sympathetic and chorda tympani are stimu- 
lated together on the one hand, or the chorda alone on the other, with 
such a strength of stimulus that the flow of saliva in the blood-flow is 
approximately the same in each case, the following results are obtained 
for the relative properties of the two specimens of saliva :— 
2 3 Stimulation of Chorda Stimulation of Chorda 
and Sympathetic only 
Saliva volume . : Equal Equal 
CO, output to blood . - Less Greater 
CO, output to saliva. e Greater Less 
Total CO, output =, About equal About equal 
Fixed CO, in saliva , - . Greater Less 
Alkalinity of saliva . é Greater Less 
Oxygen intake from blood About equal About equal 
It appears that the sympathetic is not either ‘secretory’ (since its 
stimulation does not involve the abstraction of water from the blood) of 
‘trophic’ (since its stimulation does not involve increased gaseous meta- 
bolism) in Heidenhain’s sense. At the same time it has an action 
(independent of vascular effects) which causes material to be expelled 
from the cells, not the ducts merely, anda transference of alkali from the 
blood to the saliva. This greater alkalinity probably accounts for tke 
greater percentage of organic matter in the saliva. 
Glands generally.—In so far as the above specimens may be taken as 
characteristic of secreting glands generally, the outstanding fact seems to 
be established that the volume of the secretion (i.c., the amount, of water 
which is transferred from one side of the epithelium to the other) is the 
surest index of the degree of oxidation taking place in the gland, and it is 
difficult to avoid the conclusion that there is a causal connection between 
the two phenomena. 
Technique.—Certain modifications in technique have been introduced 
as occasion has arisen. 
The Hirudin of Jacobi! has proved a most useful reagent for blood-gas 
work. In experiments upon the pancreas it has been introduced, and its 
' Obtained from E. Sachsse & Co., Leipsig-R. 
1905, Q 
