The Seventeenth Century 109 



Now I can better than before, when I was thrown on my own resources, 

 explain those sections on light which I had undertaken, where so many 

 learned men have shown before me, with whose help the work can be 

 completed more easily. For after my first outlines of the first edition, 

 others have successfully wrestled with this light, Hermannus Conringius,-^ 

 the embellishment of his age, in his De Igne Animali, the famous Jacobus 

 Holstius in De Flaynniida Cordis, Daniel Puerarius of mature judgment 

 in De Came Lucente [see Chap. XIV], and many others who, in their 

 writings, either followed my footsteps or opened up new paths to be 

 followed from the accurate observations of the more recent scholars. 



It is not surprising to find that Bartholin's treatment of the light 

 of men in Book I is full of mysticism. There are many references 

 to the Bible and to writers of antiquity. One can judge of this from 

 the titles to the first nine chapters: 



I. True light is assigned to man by his perfection. 



II. It is demonstrated from stones that light is in us. 



III. The light of man is proved by luminous minerals and vegetables. 



IV. It is proved also by the internal mixture and temperature. 

 V. Light is given to man by [internal] actions (operationes) . 



VI. We infer light in man from the condition and sufferings of the 



sick. 

 VII. The same light is produced by his natural desire. 

 VIII. Human light is proved from the quick action of [natural] causes. 

 IX. It is shown by examples that men shine. 



The remaining chapters (10 to 24) of Book I deal with light 

 from the various anatomical regions of the human body, including 

 " the shining face of Moses " (Chap. 12) and " the light of the 

 human soul " (Chap. 23) . 



Bartholin used (precious) stones, minerals, and vegetables to 

 prove that light is in all things. In dealing with precious stones 

 (Book I, Chap. 2) , the usual stories are recounted of shining car- 

 buncles, sapphires, rubies, etc., whose light is actually due to trans- 

 mitted or reflected color. Among stones in Book I, Chap. 3, sulphur 

 is mentioned as " not only shining with an external brightness, 

 but possesses a great amount of an inner light, by whose benefit, 

 once its structure has been loosened, it is lighted very quickly by 

 heat and consumed by its own light." 



Concerning the newly discovered Bolognian stone, Bartholin 

 wrote: 



Quite similar to it [sulphur] is the other mineral that began to be 

 brought forth in 1602 in the vicinity of Bologna at the time of our fathers, 



2* Hermann Conring (1606-1681), professor of philosophy and medicine at the Uni- 

 versity of Helmstadt and physician to Queen Christiana of Sweden. 



