sect, ii.] DISSERTATION SECOND. 83 



Of the twenty-seven classes into which instantiae arc 

 arranged by the author of the Novum Organum, fifteen 

 immediately address themselves to the Understanding; five 

 serve to correct or to inform the Senses ; and seven to 

 direct the hand in raising the superstructure of Art on the 

 foundation of Science. The examples given above are 

 from the first of these divisions, and will suffice for a sum- 

 mary. To the five that follow next, the general name of 

 instantiae lampadis is given, from their office of assisting 

 or informing the senses. 



Of these the instantiae januae assist the immediate ac- 

 tion of the senses, and especially of sight. The examples 

 quoted by Bacon are the microscope and telescope (which 

 last he mentions as the invention of Galileo,) and he speaks 

 of them with great admiration, but with some doubt of 

 their reality. 



The instantiae citantes enable us to perceive things 

 which are in themselves insensible, or not at all the objects 

 of perception. They cite or place things, as it were, be- 

 fore the bar of the senses, and from this analogy to judicial 

 proceedings is derived the name of instantiae citantes. 

 Such, to employ examples which the progress of science 

 has unfolded since the time of Bacon, are the airpump and 

 the barometer for manifesting the weight and elasticity of 

 air; the measurement of the velocity of light, by means of 

 the eclipses of the satellites of jupiter, and the aberration 

 of the fixed stars ; the experiments in electricity and gal- 

 vanism, and in the greater part of pneumatick chemistry. 

 In all these instances things are made known, which before 

 had entirely escaped the senses. 



The instantiae viae are facts which manifest the con- 

 tinuous progress of nature in her operations. There is a 

 propensity in men to view nature as it were at intervals, or 

 at the ends of fixed periods, without regarding her gradual 



