That is Simiacine.

He can hang on to a tree with one leg and tackle a leopard with his bare hands--that's Simiacine.

At home, in England and in Germany, they are only just beginning to find out its properties; it seems that it can bring a man back to life when he is more than half dead.

There is no knowing what children that are brought up on it may turn out to be; it may double the power of the human brain--some think it will." Jack Meredith was leaning forward, watching with a certain sense of fascination the wild, disease-stricken face, listening to the man's breathless periods.

It seemed that the fear of death, which had gotten hold of him, gave Victor Durnovo no time to pause for breath.
"Yes," said the Englishman, "yes, go on." "There is practically no limit to the demand that there is for it.