254 ON THE POISON OF ANIMALS 
sequently, if both combined in due proportions, they 
would neutralize each other; but as there is usually 
a much more copious supply of the alkaline than of 
the acid fluid, its agency would predominate, and 
scarcely a trace of red would be discerned on the lit- 
mus paper. 
Submitted to the same chemical tests, the fluid 
contained in the stomachs of spiders and that which 
flows from wounds inflicted on their bodies and limbs 
were found to be alkaline. Now if the frequency and 
suddenness with which large quantities of fluid are 
propelled into the mouths of spiders when occupied 
in extracting nutriment from thei prey be borne in 
mind, the conclusion that they must be ejected from 
the stomach through the narrow cesophagus and pha- 
rynx seems to be inevitable*, as there is not any other 
source known whence they could be derived; and it 
has been ascertained that if they are applied to litmus 
paper, which has or has not been reddened by acetous 
acid, they always produce upon it effects precisely 
similar to those caused by the gastric fluid, or rather 
by the fluid contents of the stomach, when subjected 
to such tests. I may remark that the yellow colour 
* The statement of Savigny, that some spiders have three 
pharyngeal apertures, does not appear to be applicable to several 
of our larger indigenous species, as I have not been able to detect 
more than one such aperture in Ciniflo ferox, Celotes saxatilis, 
Tegenaria ciwilis, Agelena labyrinthica, and Epeira quadrata, on 
the most careful inspection. 
