56 THE HISTORY OF CREATION. 
ascribed the coming into existence of the present species of 
animals and plants—had made numerous attempts to create 
organisms of different forms, but that these attempts had 
only partially succeeded, had often failed, and that petrifac- 
tions were nothing more than such unsuccessful attempts. 
According to others, petrifactions originated from the in- 
fluence of the stars upon the interior of the earth. 
Others, again, had the still cruder notion that the Creator 
had first made models (out of mineral substances—for 
example, of gypsum or clay) of those forms of animals and 
plants which he afterwards executed in organic substances, 
and into which he breathed his living breath; petrifactions 
were accordingly such rude inorganic models. Even as late 
as the last century these crude ideas prevailed, and it was 
assumed, for example, that there existed a special “ seminal 
air,’ which was said to penetrate into the earth with 
the water, and by fructifying the stones formed petrifactions 
or “stony flesh” (caro fossilis). 
It took a very long time before the simple and natural 
view was accepted, namely, that petrifactions are in reality 
nothing but what they appear to simple observation—the 
indestructible remains of extinct organisms. It is true the 
celebrated painter, Leonardo da Vinci, in the 15th century, 
ventured to assert that the mud which was constantly 
deposited by water was the cause of petrifactions, as it 
surrounded the indestructible shells of mussels and snails 
which lay at the bottom of the waters, and gradually turned 
them into solid stone. The same idea, was maintained in 
the 16th century by a Parisian potter, Palissy by name, 
who became celebrated on account of his invention of 
china. However, the so-called “professional men” were 
