12 Veterinary Medicine. 



3. The hypodermic use of the serum is usually to be preferred, 

 though in certain cases intravenous injection may be employed, 

 or even injection into cavities containing the organs that 

 have an elective affinity for the toxins. 



4. Use the therapeutic serum as early as possible after 

 infection. A short delay means the demand for an enormous 

 encrease of the antitoxic serum to be used, and even then in 

 some diseases (tetanus) it has little or no effect. 



5. The introduction of the antitoxin just before the in- 

 fection, or at least during the incubation stage, when as yet the 

 toxins have not united with the susceptible tissues, promises the 

 best results. 



Modifying Factors : — Physiological and Pathological. 



Many different conditions of the system disturb, modify or 

 annul the habitual operation of the agencies relied upon for im- 

 munization and serum therapy, and although such interference 

 is exceptional, yet its occasional occurrence will interfere in such 

 cases with the full success of the sanitary work based on these 

 methods. 



Both immunization and serum-therapy are largely influenced 

 by the supply of oxygen in the freely circulating blood, and, 

 when this has been interfered with by excessive or defective 

 functional activity of the thyroid, anterior pituitary body, or, 

 above all the adrenals, the protective or curative process is 

 materially affected. Sajous, who ascribes the bacteriolytic action 

 mainly to a tripsin body formed in the pancreas and spleen and 

 sent in the blood to the comparatively immune liver, or in the 

 wandering or tissue cells, claims that the abundance of this and 

 other antibodies is determined largely by the supply of adrenalin, 

 which controls the dilatation and contraction of the capillaries 

 and the quantity of blood and oxygen supplied. If the stimula- 

 tion of the adrenals by toxins is insufficient he advises to add to 

 this alkaline salts, strychnine, digitalis, etc., but there is again 

 the danger of complete arrest of adrenal function by overstimu- 

 lation. Other examples might be adduced to show that the im- 

 munization is at times an uncertain quantity and to enforce the 

 truth that the absolute extinction of the microbe by segregation 



