440 THE WORLD MACHINE 



found widely distributed over the earth ; they likewise occur 

 in meteorites, conceivably also in meteoritic dust. Some of 

 these compounds may exist in the minute particles which reach 

 the earth under the pressure of radiation. Probably it would be 

 very difficult to find anywhere upon the earth an actual synthesis 

 of these compounds now taking place. Yet there is no mystery 

 about them. They are formed and unformed, daily and hourly, 

 in the laboratory and in industrial processes. We have, more- 

 over, excellent reason for supposing their natural production 

 at some period or other of the earth's history. In brief, a given 

 substance that one might pick up in the street might have been 

 produced by a chemist ; it might have been formed when the 

 earth was at the temperature of a blast-furnace ; it might have 

 come from some celestial stithy at ten million times the distance 

 of the sun. 



So with life. Forms of life may reach us in one way and 

 another from every part of the universe ; but at the same time 

 its spontaneous production from inorganic materials may be 

 taking place on the earth without cease, let us say, under the 

 tremendous pressures existent at the bottom of the sea, or in 

 warm springs of peculiar chemical content. In forty or fifty 

 years a Berthellot or a Fischer may be producing endless varieties 

 as readily as they do new chemical varieties of sugar now. 



It seemed worth while to be somewhat explicit upon the 

 point in view of the extraordinary persistence of the idea that 

 the chemical processes of life are any whit more mysterious 

 than the chemical processes which produce salt or sugar or 

 glass, or result in the burning of coal in the grate. The pre- 

 ferences of the atoms, their tendency to combination what in 

 vague phrase we call chemical affinity is one of the three or 

 four great world mysteries. The especial atomic association 

 which displays the phenomena of life is not now a mystery 

 save in the most restricted sense. It is no more of a mystery, 

 I let us say, than the laws of the weather. 



The parallel is perhaps very close. The weather sharp now 

 knows the most, though not all, of the physical conditions which 

 produce the varieties and eccentricities of atmospheric pheno- 

 mena. The bio-chemist understands the most, but not all, of 

 the physical conditions which result in the display of life by 

 " inert " matter. But he cannot, as yet, follow these conditions 

 sufficiently close to produce life, just as the weather-prophet 



