12 CLASSICS OF MODERN SCIENCE 



With regard to heat, man possesses abundant means and power; 

 but his observation and inquiry are defective in some respects, and 

 those of the greatest importance, notwithstanding the boasting of 

 quacks. For the effects of intense heat are examined and observed, 

 whilst those of a more gentle degree of heat, being of the most fre- 

 quent occurrence in the paths of nature, are, on that very account, 

 least known. We see, therefore, the furnaces, which are most 

 esteemed, employed in increasing the spirits of bodies to a great 

 extent, as in the strong acids, and some chemical oils ; whilst the 

 tangible parts are hardened, and, when the volatile part has escaped, 

 become sometimes fixed; the homogeneous parts are separated, and 

 the heterogeneous incorporated and agglomerated in a coarse lump; 

 and (what is chiefly worthy of remark) the junction of compound 

 bodies, and the more delicate Conformations are destroyed and con- 

 founded. But the operation of a less violent heat should be tried 

 and investigated, by which more delicate mixtures, and regular 

 conformations may be produced and elicited, according to the example 

 of nature, and in imitation of the effect of the sun, which we have 

 alluded to in the aphorism on the instances of alliance. For the works 

 of nature are carried on in much smaller portions, and in more delicate 

 and varied positions than those of fire, as we now employ it. But 

 man will then appear to have really augmented his power, when the 

 works of nature can be imitated in species, perfected in power, and 

 varied in quantity ; to which should be added the acceleration in point 

 of time. Rust, for instance, is the result of a long process, but crocus 

 martis is obtained immediately ; and the same may be observed of 

 natural verdigris and ceruse. Crystal is formed slowly, whilst glass 

 is blown immediately : stones increase slowly, whilst bricks are baked 

 immediately, etc. In the mean time (with regard to our present 

 subject) every different species of heat should, with its peculiar 

 effects, be diligently collected and inquired into ; that of the heavenly 

 bodies, whether their rays be direct, reflected, or refracted, or con- 

 densed by a burning-glass ; that of lightning, flame, and ignited 

 charcoal ; that of fire of different materials, either open or confined, 

 straitened or overflowing, qualified by the different forms of the 

 furnaces, excited by the bellows, or quiescent, removed to a greater 

 or less distance, or passing through different media ; moist heats, 

 such as the balneum Marico, and the dunghill ; the external and in- 



