6 ANAPHYLAXIS AND ANTI-ANAPHYLAXIS 



Richet and Portier determined the dose of actino- 

 congestin which could be injected into the veins of 

 a dog without killing it; if they exceeded this dose 

 they killed the dog, though not immediately. The 

 animal did not exhibit anything that gave rise to 

 uneasiness immediately after the injection, and it 

 was only after some time that there appeared symp- 

 toms which became progressively aggravated during 

 the course of two days and terminated fatally gener- 

 ally about the third day. 



But events took a different course in a dog which 

 had previously received a weak dose of congestin ; it 

 was sufficient to inject it with a dose equal to one- 

 twentieth of the first dose in order to produce, after 

 only a few seconds, the sudden onset of serious 

 symptoms such as violent attacks of vomiting, 

 dyspnoea, paraplegia, etc. 



" The characteristic experiment," says Richet,^ 

 *' which revealed the phenomenon to me in all its 

 undoubted clearness was carried out on a dog called 

 Neptune. He was an exceptionally vigorous and 

 healthy dog. He had first of all received o-i c.c. 

 of glycerinated fluid (glycerinated extract of the 

 tentacles of Actiniae) without any ill-effects result- 

 ing. Twenty-two days afterwards, when he was 

 in excellent health, I injected him with the same 

 dose of o-i c.c. He then immediately became ex- 

 ceedingly ill — that is to say, some seconds after the 

 termination of the injection; his breathing became 

 distressed and he panted; he could scarcely drag 

 himself along; he lay on his side, was seized with 

 diarrhoea and the vomiting of blood. Sensation be- 

 came abolished, and he died in thirty-five minutes." 



In other words, the dose of congestin which had no 

 effect on the normal dog rendered the sensitised dog 

 extremely ill and killed him. 



1 Ch. Richet. " L'anaphylaxie," p. 3; ed. F. Alcan. 



