FUNDAMEKTAL PEIKCIPLES OP DISEASE. 37 



or on the legs, as so often used. Blisters, iodin, and many other 

 irritants are used in a similar way. 



Constitwtiondl treatment in inflammation is designed to reduce the 

 current of blood, which is the fuel for the inflammation in the dis- 

 eased part, to quiet the patient, and to combat the fever or general 

 effects of the trouble in the system, and to favor the neutralization or 

 elimination of the products of the inflammation. 



Eeduction of blood is obtained in various ways. The diminution 

 of the quantity of the blood lessens the amount of pressure on the 

 vessels, and, as a sequel, the volume of it which is carried to the point 

 of inflammation; it diminishes the body temperature or fever; it 

 numbs the nervous system, which plays an important part as a con- 

 ductor of irritation in diseases. 



Blood-letting is the most rapid means, and frequently acts like a 

 charm in relieving a commencing inflammatory trouble. One must 

 remember, however, that the strength of the body and repair depend 

 on the blood; hence blood-letting should be practiced only in full- 

 blooded, well-nourished animals and in the early stages of the 

 disease. 



Cathartics act by drawing off a large quantity of fluid from the 

 blood through the intestines, and have the advantage over the last 

 remedy of removing only the watery and not the formed elements 

 from the circulation. The blood cells remain, leaving the blood as 

 rich as it was before. Again, the glands of the intestines are stimu- 

 lated to excrete much waste matter and other deleterious material 

 which may be acting as a poison in the blood. 



Diuretics operate through the kidneys in the same way. 



Diaphoretics aid depletion of the blood by pouring water in the 

 form of sweat from the surface of the skin and stimulating the dis- 

 charge of waste material out of its glands, which has the same effect 

 on the blood pressure. 



Antipyretics are remedies to reduce the temperature. This may be 

 accomplished by depressing the center in the brain that controls heat 

 production. Some coal-tar products are very effective in this way, 

 but they have the disadvantage of depressing the heart, which should 

 always be kept as strong as possible. If they are used it must be with 

 knowledge of this fact, and it is well to give heart tonics or stimu- 

 lants with them. The temperature of the body may be lowered by 

 cold packs or by showering with cold water. This is a most useful 

 procedure in many diseases. 



Depressants are drugs which act on the heart. They slow or 

 weaken the action of this organ and reduce the quantity and force 

 of the current of the blood which is carried to the point of local 

 disease; they lessen the vitality of the animal, and for this reason 

 are now used much less than formerly. 



