124 VETERINARY SURGICAL THERAPEUTICS. 
This blade had remained in the heart without giving rise to the slightest 
trouble. Articular or tendinous synovial membranes behave like the 
serous nembranes of splanchnic cavities. 
The tolerance of the media of the eye is also especially related to the 
aseptic or infecting condition of the body which has penetrated them; 
the iris, vitreous humor, and the retina, however, are more susceptible 
than the crystalline lens and the serous membrane of the anterior 
chamber. 
In the foot of the horse, foreign bodies produce, almost always. 
rapidly, serious troubles, on account of the complex structure of that 
organ, of the ordinarily infectious character of the traumatism, and of 
the compression to which the injured parts are submitted. 
Animate foreign bodies produce very different effects, according to the 
species, the number, their properties and the tissues upon which they are 
fixed. How many intermediate ‘degrees can be observed between the 
weak reaction of the stomachal mucous membrane of the horse from 
cestri, and the intolerance of the nervous centers towards the parasites 
which are carried to them by the blood. 
To liguid foreign bodies the susceptibility of the organs is no less 
variable. No serious troubles result, ordinarily, from the introduction 
of serosity poured into closed traumatic lesions. Liquids, aseptic and 
not toxic, injected under the skin, into muscles, serous membranes or 
blood-vessels, are also well supported. But the tissues are very suscep- 
tible to the contact of some organic liquids obtained from their natural 
canals (urine, bile, saliva). The escape of bile, or of urine, into the 
peritoneum is often fatal. Medicamental solutions injected without. 
sufficient aseptic care, ordinarily bring on suppuration or other infec- 
tious accidents. The contents of hydatic cysts and of all morbid secre- 
tions, generally speaking, are badly tolerated. 
Gases, considered as foreign bodies, offer little interest. All are 
harmless, except those that possess toxic properties, and are tolerated 
by the tissues without trouble. The benignity of traumatic emphysema, 
even when it is more or less generalized, is well known. Phenomena 
of intolerance are observed only when gases hold infectious agents in. 
suspension. 
The therapeutics of foreign bodies presents very different require- 
ments, according to their nature, their size and their aseptic or infectious 
state. The preceding considerations show the relative innocuity of 
metallic bodies compared with organic substances, and the remarkable 
tolerance of the tissues for the former, when they are small and aseptic. 
The organism does not try to get rid of them; it only defends itself 
against contact with them; it isolates them with a circular neoformation 
resulting in an encysting membrane. No immediate interference is 
necessary for those, unless they are so nearly on the surface that their 
