82 CLINICAL BACTERIOLOGY AND 



When the dose has been too small, we get an immediate 

 positive phase of short duration and of little or no curative 

 value. Thus : 



Fig. 35. — Dose of Vaccine is too Small. 



On the contrary, if the dose has been too large, we get 

 an immediate fall of the index. Nature's balance has been 

 so upset she cannot assimilate, so to speak, the dose; great 

 depression sets in, and several days may pass before a 

 restoration to the previous state takes place. 



Fig. 36. — Dose of Vaccine is too Large. 



In the horse we have never noticed this phase, and have 

 given doses very many times greater than orthodox present- 

 day teaching suggests. In the case of the dog, we confess 

 to having a few isolated instances of apparent temporary 

 collapse, etc., following upon vaccine-therapy, but never 

 with fatal results. 



The immunizer should aim at index No. 1 as his ideal to 

 follow out in practice. 



If he get a reaction such as is shown in index No. 2, 

 with no curative results, he should not condemn the treat- 

 ment, but persevere and increase his dose. 



Index No. 3, in the hands of a careful practitioner, 

 should never occur ; and if it does, it ought to teach him to 

 be less heroic and more careful in his future dealings with 

 vaccines. 



As already stated, and we repeat it again to emphasize 

 the fact, it is a "sine qua non," when the opsonic index falls, 



