164 NOVUM ORGANUM 



transparency. The reason is the same as in the above in 

 stances. 40 



XXIY. In the third rank of prerogative instances we 

 will class conspicuous instances, of which we spoke in our 

 first vintage of the form of heat, and which we are also wont 

 to call coruscations, or free and predominant instances. 

 They are such as show the required nature in its bare sub 

 stantial shape, and at its height or greatest degree of power, 

 emancipated and free from all impediments, or at least over 

 coming, suppressing, and restraining them by the strength 

 of its qualities; for since every body is susceptible of many 

 united forms of natures in the concrete, the consequence is 

 that they mutually deaden, depress, break, and confine each 

 other, and the individual forms are obscured. But there are 

 some subjects in which the required nature exists in its. full 

 vigor rather than in others, either from the absence of any 

 impediment, or the predominance .of its quality. Such in 

 stances are eminently conspicuous. But even in these care 

 must be taken, and the hastiness of the understanding 

 checked, for whatever makes a show of the form, and forces 

 it forward, is to be suspected, and recourse must be had to 

 severe and diligent exclusion. 



For example, let heat be the required nature. The ther 

 mometer is a conspicuous instance of the expansive motion, 

 which (as has been observed) constitutes the chief part of 

 the form of heat; for although flame clearly exhibits expan 

 sion, yet from its being extinguished every moment, it does 

 not exhibit the progress of expansion. Boiling water again, 



r The mineral kingdom, as displaying the same nature in all its gradations, 

 from the shells so perfect in structure in limestone to the finer marbles in 

 which their nature gradually disappears, is the great theatre for instances 

 of migration. Ed. 



