240 VENOMS 
this immunity to be transmitted in certain cases by heredity, and 
thus we can understand how the profession of snake-charmer was 
hereditary in certain native families in India or Egypt. 
With reference to this subject, Professor Landouzy, in his fine 
work on serum therapeutics, quotes a passage from ‘The Pharsalia ” 
of Lucan describing, in the year 60 a.D., the customs of the Psylli, 
a people encountered by the army of Cato during its sojourn in 
Africa. This passage is so interesting that I cannot refrain from 
reproducing it :— 
‘ Alone unharmed of all who till the earth 
By deadly serpents, dwells the Psyllian race. 
Potent as herbs their song; safe is their blood, 
Nor gives admission to the poison germ 
E’en when the chant has ceased. Their home itself 
Placed in such venomous tract and serpent-thronged 
Gained them this vantage, and a truce with death, 
Else could they not have lived. Such is their trust 
In purity of blood, that newly born 
Each babe they prove by test of deadly asp 
For foreign lineage. So the bird of Jove 
Turns his new fledglings to the rising sun, 
And such as gaze upon the beams of day 
With eyes unwavering, for the use of heaven 
He rears ; but such as blink at Phcebus’ rays 
Casts from the nest. Thus of unmixed descent 
The babe who, dreading not the serpent touch, 
Plays in his cradle with the deadly snake.” 
The only scientific conclusion to be drawn from the facts and 
statements that we have just set before the reader is that, under 
certain circumstances, man can unquestionably acquire the faculty 
of resisting intoxication by snake-venom, by conferring upon him- 
self a veritable active immunity by means of repeated inoculations 
of venom. We shall shortly see that the case is the same with 
regard to animals. 
1 “The Pharsalia of Lucan, translated into blank verse by Edward Ridley, 
Q.C., sometime Fellow of All Souls’ College, Oxford.” (London: Longmans, 
Green and Co., 1896). Book ix., p. 296, lines 1,046 to 1,065. 
