The sheep, fine healthy beasts, were herded into a clear space; Roux and Chamberland lighted their alcohol lamps and gingerly unpacked their glass syringes and shot five drops of the first vaccine--the anthrax bacilli that would kill mice but leave guinea-pigs alive, into the thighs of twenty-four of the sheep, one of the goats, and half of the cattle. The beasts got up and shook themselves and were labeled by a little gouge punched out of their ears. Then the audience repaired to a shed where Pasteur harangued them for half an hour--telling them simply but with a kind of dramatic portentousness of these new vaccinations and the hopes they held out for suffering men. Twelve days went by and the show was repeated. The crowd was there once more and the second vaccine--the stronger one whose bacilli had the power of killing guinea-pigs but not rabbits--was injected, and the animals bore up beautifully under it and scampered about as healthy sheep, goats and cattle should do. The time for the fatal final test drew near; the very air of the little laboratory became finicky; the taut workers snapped at each other across the Bunsen flames. Pasteur was never so appallingly quiet--and the bottle washers fairly jumped across the room to fill his growled orders. Every day Thuillier, Pasteur’s new youngest assistant, went out to the farm to put his thermometer carefully under the tails of the inoculated animals to see if they had fever--but thank God, every one of them was standing up beautifully under the heavy dose of the vaccine that was not quite murderous enough to kill rabbits. While the heads of Roux and Chamberland turned several hairs grayer, Pasteur kept his confidence, and he wrote, with his old charmingly candid opinion of himself: “If success is complete, this will be one of the finest examples of applied science in this country, consecrating one of the greatest and most fruitful discoveries.” His friends shook their heads and lifted their shoulders and murmured: “Napoleonic, my dear Pasteur,” and Pasteur did not deny it. IV Then on the fateful thirty-first of May all of the forty-eight sheep, two goats, and several cattle--those that were vaccinated and those to which nothing whatever had been done--all of these received a surely fatal dose of virulent anthrax bugs. Roux got down on his knees in the dirt, surrounded by his alcohol lamps and bottles of deadly virus, and awed the crowd by his cool flawless shooting of the poisonous stuff into the more than sixty animals.