The Seventeenth Century 117 



Major did not realize that his little drop like a pearl which shone 

 so brightly was really a worm. The proof was to come later with 

 publication of the true situation by De la Voye and Auzout (1666) 

 in the Memoires of the French Academy. 



Sachs reaUzed that the mere statement that all things contain 

 light is not entirely satisfactory and took considerable pains to point 

 out (p. 948) , 



in regard to the light of crabs shining at night, it is certain that the 

 shells of what are generally known as crabs, have no inborn light, and 

 do not spread it in the dark unless they have previously advanced to a 

 very definite stage of putrefaction. Once they have gone beyond that, 

 they immediately lose the light; not even the shells of lobsters give forth 

 such light, whereas most living beings and plants in a certain stage of 

 putrefaction do shine. From various experiments which I have col- 

 lected, it can be shown that the heads, bones, scales, humors, and the 

 flesh of most marine fish shine when thrown out in the dark, once they 

 have reached a certain degree of putrefaction. 



Sachs mentioned Bacon's experiments with rotten wood and then 

 indicated that there was another side to the story, for " Kircher 

 tells miraculous things about the humor of the pholades and the 

 plumones marini [jellyfish], but he seems to assume that the light 

 in their humors is there by virtue of an innate principle without 

 previous putrefaction." 



It was indeed a difficult thing to distinguish between flesh covered 

 with the growth of luminous bacteria, wood containing luminous 

 fungi, the jellyfish or Pholas shining with their own light, and the 

 electrical discharge, ignis lambens, that frequently appeared on the 

 hair of animals or skin and clothes of humans. The resolution of 

 such diverse luminous phenomena was to require a vast amount of 

 further study. 



Bartholin's influence is also well shown in a rather interesting 

 book by Filippo Buonanni (1638-1725), a Jesuit and inspector of 

 the Museum Kircherianum in Rome. It was entitled Ricreazione 

 dell'Occhio et della Mente nell'Osservazione delle Chiocciole, Roma, 

 1681. A Latin edition appeared in 1684. This type of book might 

 be considered the forerunner of the popular natural history of today, 

 for the author described luminous fish and various luminous inverte- 

 brates, and also proposed problems. The material was taken from 

 previous writers, particularly Bartholin. Problema XXXIV took up 

 the question, " Why does Balanus ^^ [i. e., Pholas dactylus, the lumi- 



'^ Balanus means an acorn or some fruit of the same shape, or a date. Buonanni 

 used the word for the Italian, datti, a local name for Pholas dactylus. The same 

 account is to be found in Buonanni's later book, Museum kircherianum (Rome, 1709) . 



