ORIGIN OF LIFE, SEX, SPECIES, ETC. 209 



solidity and had been in this condition long enough 

 to permit oxygen and hydrogen to combine, and some 

 of the vapor of water to liquefy. It seems also very 

 probable, from their atomic weights and from the 

 temperatures at which they liquefy, that some of 

 the compounds of the class of substances now to 

 be mentioned, viz., calcium, phosphorus, potassium, 

 sodium, sulphur, etc., which will hereafter be referred 

 to as secondary elements of life were, at that time, 

 in the gaseous form, present in combination with 

 either one or several of the elements next to be 

 named, viz., oxygen, hydrogen, nitrogen, carbon, 

 which will hereafter be distinguished as primary 

 elements of life; while others of these compounds, 

 as oxides, acids, and salts, were held in solution by 

 the portions of water which had liquefied from its 

 previous vaporous mist or steam condition. 



In the form of living organisms (plant and brute), 

 and of the remains and products of these, a vast 

 quantity of material is now present on the surface 

 of the earth, and in the water which covers it. By 

 far the largest part of this in weight and bulk con- 

 sists of the primary elements of life in various com- 

 binations. All this just before life began must 

 have been a part of the atmosphere ; so must also 

 have been the water of crystallization contained in 

 many minerals; also of the water now existing as 

 ice and snow near the polar regions and elsewhere 

 on high mountain ranges and plateaus: also of 

 most of the water now in the oceans, lakes, rivers, 



