140 NOVUM ORGANUM 



also, that the quarters of the heavens produce a greater heat 

 (though not perceptibly), in proportion as they are adorned 

 with a greater number of stars, particularly those of the 

 first magnitude. 



19. On the whole, the heat of the heavenly bodies is 

 augmented in three ways: 1. The approach to the perpen 

 dicular; 2. Proximity or their perigee; 3. The conjunction 

 or union of stars. 



20. There is a very considerable difference between the 

 degree of heat in animals, and even in the rays of the heav 

 enly bodies (as they reach us), and the heat of the most gen 

 tle flame, and even of all ignited substances, nay, liquids, 

 or the air itself when unusually heated by fire. For the 

 flame of spirit of wine, though diffused and uncollected, is 

 yet able to set straw, linen, or paper on fire, which animal 

 heat, or that of the sun, will never accomplish without a 

 burning-glass. 



21. There are, however, many degrees of strength and 

 weakness in flame and ignited bodies: but no diligent in 

 quiry has been made in this respect, and we must, therefore, 

 pass it hastily over. Of all flames, that of spirits of wine 

 appears to be the most gentle, except perhaps the ignis 

 fatuus, or the flashes from the perspiration of animals. 

 After this we should be inclined to place the flame of light 

 and porous vegetables, such as straw, reeds, and dried 

 leaves; from which the flame of hair or feathers differs but 

 little. Then, perhaps, comes the flame of wood, particu 

 larly that which contains but little rosin or pitch; that of 

 small wood, however (such as is usually tied up in fagots), 

 is milder than that of the trunks or roots of trees. This can 

 be easily tried in iron furnaces, where a fire of fagots or 

 branches of trees is of little service. Next follows the flame 



