68 
ESSAY ON SECRETION. 
From this cause, these two secretions are intimately related 
the one to the other. Taking albumen as representing the 
composition of the muscular tissue, we find that either of 
these secretions taken alone would only remove part of the 
products of its disintegration ; while their joint composition 
so nearly resembles that of albumen, that we may fairly con¬ 
clude that its elements would be entirely removed from the 
body by their joint agency. 
The nature of the food will also exert an important modi¬ 
fying influence upon the secretions, by the same process of 
altering the properties of the blood, thus necessarily changing 
the character of the secretions drawn from that fluid. 
Then, further, by virtue of the influence of the nervous 
system upon the vessels conveying blood to the various 
secreting organs, and distributing the blood through them, 
we may have at one time a rapid or at another a slow secretion, 
or even an entire suspension of the secretory process ; having 
in the one case a large quantity of blood within the vessels of 
the gland, and in the other a quantity insufficient for the due 
performance of its function. 
This I believe to be the only way in which the secretory 
processes are under nervous influence; for, as I have en¬ 
deavoured to show you, the act of secretion is dependent upon 
the growth of cells, and this process of cell growth does not 
depend for its continuance upon nervous activity ; therefore 
there is no necessity for supposing, as some of the older 
physiologists used to do, that a kind of galvanic current con¬ 
veyed by the nerves is necessary for the due performance of 
the secretory action. 
You will now be able to understand how it is that inflam¬ 
mation of any gland is able to put a stop to its secretory 
function: for you are aware, that in inflammation you have a 
suspension of the circulation in some of the vessels, and con¬ 
sequently the secreting cells cannot withdraw the necessary 
materials for the formation of the secretion from the blood. 
But as it is seldom the case that all the vessels are 
blocked up, you may have one portion of the gland still able 
to secrete, and thus only a partial suspension of its function 
takes place. 
You will also see how it is that inflammation may destroy 
for ever the secretory power of a gland, either by blocking up 
with fibrinous exudations the small ramifications and vesi¬ 
cular terminations of its ducts, or by so altering their structure 
as to prevent the reformation of the secreting cells. 
There now remain two other modifying causes to be con¬ 
sidered. First, the power which one gland has to secrete a 
