NATURAL CONDENSATION. 297 



even, in fact, bring it packed in coal, were it not for the in- 

 convenience they would incur in that case in the work of 

 unpacking it." 



In speaking thus of hydrogen and carbon, which are the 

 constituents of illuminating gas, as packed in paraffine and 

 in coal, Lawrence used language, it must be confessed, in a 

 somewhat figurative sense ; but these materials do certain- 

 ly exist in these substances in a very highly condensed and 

 concentrated condition. Indeed, Nature seems to have the 

 power of carrying into eifect this kind of packing in a most 

 extraordinary degree. 



Water, for example, is composed of the two substances 

 oxygen Snd hydrogen, both of which in their ordinary con- 

 dition, as known to us, appear in the form of a gas. Na- 

 ture, in combining these substances in the form of water, 

 brings enormous volumes of them into very small compass, 

 and retains them in that condition without any external 

 force of compression or any means of confinement what- 

 ever. Man can not produce this condensation by a press- 

 ure of a hundred and fifty atmospheres. 



I shall presently explain what is meant by an atmosphere 

 as a measure of pressure, though the explanation will not 

 help the reader to form any distinct conception of what a 

 pressure of a hundred and fifty atmospheres is, as no one 

 can form any adequate idea of such enormous forces ex- 

 cept those who have witnessed the production of them 

 and observed practically some of their effects. 



Somewhat in the same way by which the powers of na- 

 ture hold the naturally gaseous substances of oxygen and 

 hydrogen in so very compact and concentrated a condition 

 in water, do they also hold the carbureted hydrogen in the 

 paraffine of the -candle and in coal. In the case of coal, the 

 quantity held within a given space varies much, according 

 to the different qualities of the coal, and to other circunv 

 N2 



