ON THE EFFECTS OF ACRID POISONS. 239 
tion at all, no symptom whatever has followed the injection of 
half a drachm of kreosote mixed with water. AVhen double that 
quantity has been injected pure, death has immediately ensued, 
apparently occasioned by the obstruction to the pulmonary cir¬ 
culation, the lungs having been found black and gorged with 
blood, which seemed composed of minute granules mixed with a 
fluid of inky blackness. 
In the present state of animal chemistry, and in reasoning 
from so small a number of experiments, any explanation of the 
phenomena here detailed must be held to be conjectural. But 
such is in fact one great object of the Meeting. It would ap¬ 
pear in the first place that arsenic injected into the veins exerts 
an influence primarily on the small intestines, that there at 
least its effect as an irritant begins ; and as far as these experi¬ 
ments go it would seem that the upper part of the duodenum 
was the first to exhibit traces of its action. In the first expe¬ 
riment the large intestines were absolutely free from any organic 
change, and the stomach but slightly participated. When a longer 
period had elapsed, other portions of the gastro-intestinal mucous 
membrane have become inflamed, and other and remote parts 
have been implicated. Such a series of effects is seen in cases of 
poisoning by arsenic. In these the epigastrium is first referred 
to as the seat of derangement; then the whole alimentary canal; 
next the skin is the seat of an efflorescence, or rash, the uri¬ 
nary organs often participating at the same time. After a 
longer or shorter interval a crop of pustules will appear; later 
yet the nervous system is affected; paralysis comes on. 
' Whether the bones would eventually become affected, as is the 
case with the cattle in the neighbourhood of manufactories 
where arsenical exhalations are generated, can only be inferred. 
In animals thus situated the joints become inflamed, anchyloses 
take place, and the bones enlarge and eventually become carious. 
The more minute series of vessels through which the fluids may 
be required to pass previous to entering into these various struc¬ 
tures, as well as a diminished susceptibility in them, and the 
necessity consequently for a repetition of the stimuli, may perhaps 
offer some explanation of these progressive affections. That 
the vascularity excited by arsenic taken into the stomach will 
doubtless be allowed to result from some chemical effect. In¬ 
flammation would not be set up by the application of a merely 
inert powder to a mucous surface from simple contact. The 
cravings of hunger of certain Indians are appeased by devouring 
clay without exciting inflammation. Nor can the angular shape 
of the minute crystals be, as was formerly conjectured, the cause 
of the excitement of inflammation, for we know that large quail- 
