THE sun's spots. 63 



phere ; and that the power of radiating light to vivify the 

 vegetation of our Earth does not appertain to the earthy nu- 

 cleus of the Sun's body, but to the luminous covering by which 

 it is enveloped." This view of the physical condition of the 

 Sun's body, which has hitherto been but little regarded in the 

 history of astronomy, presents considerable similarity with the 

 opinions maintained in the present day.=^ 



* I would, in the first place, give in the original the passages to which 

 I refer in the text, and to which my attention was directed by a learned 

 work of Clemens. {Giordano Bruno nndNicoIaus von Ctt«ar,1847,$101.) 

 Cardinal Nicolaus de Cusa (whose family name was KhrypfFs, i. e., Crab) 

 was born at Cues, on the Moselle. He thus writes in the twelfth chap- 

 ter of the second book of the Treatise De docta Ignorantia (Nicolai de 

 Cusa Opera, ed. Basil, 1565, p. 39), a work that was much esteemed 

 at that age : " Neque color nigrediuis est argumentum vilitatis Terrae ; 

 nam in Sole si quis esset, non appareret ilia claritas qure nobis : consid 

 erato enim corpore Solis, tunc habet quandam quasi terram centrali- 

 oi-em, et quandam luciditatem quasi ignilem circumferentialem, et in 

 medio quasi aqueam nubem et a^rem clariorem, quemadmodum terra 

 ista sua elementa." " Blackness of color is no proof of the inferiority 

 of the Earth's substance ; for to an inhabitant of the Sun, if such there 

 be, the same brilliancy of appearance would not be presented as to us: 

 if we consider the Sun's body, we shall conclude that it consists of a 

 certain earthy substance in the center, surrounded by a luminous mat- 

 ter, partaking, perhaps, of the nature of fire, and in the midst a sort of 

 aqueous clouds and brighter atmosphere, resembling the elements of 

 which the Earth consists." To this are appended the words Paradoxa 

 and Hypni; by the last of which, he probably understands {hvvnvLa) 

 certain speculations, vague and bold hypotheses. In the long Treatise, 

 Exercitationes ex Sermonibus Cardinalis {Opera, p. 579), I again find 

 the following comparison : " Sicut in Sole considerari potest natura cor- 

 poralis, et ilia de se non est magnse virtutis" (notwithstanding the at- 

 traction of masses or gravitation!) " et non potest virtutem suam aliis 

 corporibus communicare, quia non est radiosa ; et alia natura lucida ilia 

 anita, ita quod Sol ex unione utriusque naturae habet virtutem quae suf- 

 ficit huic sensibili mundo, ad vitam innovandam in vegetabilibus et an- 

 iraalibus, in elementis et mineralibus per suam influentiam radiosam. 

 Sic de Christo, qui est Sol justitiae . . . ." "As in the Sun may be 

 supposed to exist a corporeal nature, which of itself is of no great effi- 

 cacy, and can not communicate its virtues to other bodies, because it is 

 not radiant, and another nature united with this ; so that the Sun, from 

 the union of the two natures, has a virtue which suffices for this sensi- 

 ble world, to renew life in vegetables and animals, in elements and 

 minerals, by its own radiant influence. So from Christ, the Sun of Jus- 

 tice . . . ." Dr. Clemens thinks that all this must be more than a 

 mere felicitous presentiment. It appears to him unlikely that Cusa, in 

 the expressions " Considerato corpore Solis ;^^ "in Sole considerari po- 

 ' test . . . ." " could have appealed to experience, without a tolerably 

 accurate observation of the Sun's spots, both their darker portions and 

 the penumbrae." He also conjectures " that the penetration of the phi- 

 losopher may have been in advance of the results of the science of his 

 age, and that his views may have been influenced by discoveries which 



