154 NOVUM ORGANUM 



occupy a greater space than before. This difference is 

 principally seen in flame, where the smoke or thick vapor 

 is clearly dilated and bursts into flame. 



It is also shown in all boiling liquids, which swell, rise, 

 and boil up to the sight, and the process of expansion is 

 urged forward till they are converted into a much more 

 extended and dilated body than the liquid itself, such as 

 steam, smoke, or air. 



It is also shown in wood and combustibles where exuda 

 tion sometimes takes place, and evaporation always. 



It is also shown in the melting of metals, which, being 

 very compact, do not easily swell and dilate, but yet their 

 spirit, when dilated and desirous of further expansion, forces 

 and urges its thicker parts into dissolution, and if the heat 

 be pushed still further, reduces a considerable part of them 

 into a volatile state. 



It is also shown in iron or stones, which though not 

 melted or dissolved, are however softened. The same cir 

 cumstance takes place in sticks of wood, which become flexi 

 ble when a little heated in warm ashes. 



It is most readily observed in air, which instantly and 

 manifestly expands with a small degree of heat, as in Inst. 

 38, Tab. 3. 



It is also shown in the contrary nature of cold ; for cold 

 contracts and narrows every substance; 36 so that in intense 

 frosts nails fall out of the wall and brass cracks, and heated 

 glass exposed suddenly to the cold cracks and breaks. So 



35 To show the error of the text, we need only mention the case of water, 

 which, when confined in corked vases, and exposed to the action of a freezing 

 atmosphere, is sure to swell out and break those vessels which are not suffi 

 ciently large to contain its expanded volume. Megalotti narrates a hundred 

 other instances of a similar character. Ed. 



