This announcement called into the field a phalanx of observers, and the highest authorities in biological science engaged themselves afresh upon the problem. The experiments necessary to test the matter can be followed or repeated by any one possessing the slightest manipulative skill. Glass vessels are three-parts filled with infusions of hay or any organic matter. They are boiled to kill all germs of life, and hermetically sealed to exclude the outer air. The air inside, having been exposed to the boiling temperature for many hours, is supposed to be likewise dead; so that any life which may subsequently appear in the closed flasks must have sprung into being of itself. In Bastian's experiments, after every expedient to secure sterility, life did appear inside in myriad quantity. Therefore, he argued, it was spontaneously generated. But the phalanx of observers found two errors in this calculation. Professor Tyndall repeated the same experiment, only with a precaution to insure absolute sterility suggested by the most recent science--a discovery of his own. After every care, he conceived there might still be undestroyed germs in the air inside the flasks. If the air were absolutely germless and pure, would the myriad-life appear? He manipulated his experimental vessels in an atmosphere which under the high test of optical purity--the most delicate known test--was absolutely germless. Here not a vestige of life appeared. He varied the experiment in every direction, but matter in the germless air never yielded life. The other error was detected by Mr. Dallinger. He found among the lower forms of life the most surprising and indestructible vitality. Many animals could survive much higher temperatures than Dr. Bastian had applied to annihilate them. Some germs almost refused to be annihilated--they were all but fire-proof. These experiments have practically closed the question. A decided and authoritative conclusion has now taken its place in science. So far as science can settle anything, this question is settled. The attempt to get the living out of the dead has failed. Spontaneous Generation has had to be given up. And it is now recognized on every hand that Life can only come from the touch of Life. Huxley categorically announces that the doctrine of Biogenesis, or life only from life, is "victorious along the whole line at the present day."[34] And even while confessing that he wishes the evidence were the other way, Tyndall is compelled to say, "I affirm that no shred of trustworthy experimental testimony exists to prove that life in our day has ever appeared independently of antecedent life."[35]