fundamental discovery and its practical utilization came close together. 

 A British scientist, Alexander Fleming, took an interest in certain 

 species of bacteria, keeping them alive on gelatine, taking care that 

 no foreign spore entered his culture. Nevertheless, a spore of mould 

 did enter. A green spot arose and developed. Fleming recognized 

 it as the Pénicillium notatum^ in which he was in no way interested. 

 This mould was even a nuisance, for all around it the cultures of 

 bacteria ceased to develop. 



Fleming could have thrown out the whole preparation and started 

 another culture, taking still more care to avoid all contamination. But 

 for what reason could the bacteria not live in the neighbourhood of 

 the mould ? A commonplace observation, perhaps. But in biology no 

 fact is commonplace. Fleming studied the phenomenon at closer 

 range. Other investigators followed him in this direction and much 

 more rapidly than Oersted's discovery (we are in the twentieth century) 

 Fleming's observation bore fruit. Everyone knows it. The Pénicillium 

 notatum secretes in minute quantity a new body, penicillin. It is toxic 

 for the germs which cause certain maladies. Uncounted cures will be 

 made presently, thanks to it and to other antibiotics which were 

 discovered as an indirect result of the researches of one man. 



The scientist, whether physicist, chemist or oceanographer-, makes 

 investigations then, first out of a taste for research; and if a new region 

 of the earth, of the subsoil, of the atmosphere, or of the oceans opens 

 up before him, if a new phenomenon or a new substance is discovered, 

 he looks forward, thinking of the future. The work has not been done 

 in vain. 



By inventing an instrument able to navigate freely about the ocean- 

 floor, I satisfied my taste for invention and, I trust, opened a door in 

 oceanography. 



[ xiii ] 



