LIGNUM NEPHEITICUM SAFFOED. 273 



In 1646 Athanasiiis Kircher, a German Jesuit living in Rome, 

 celebrated for his great learning and his contributions to science, 

 published an account of Lignum nephriticum in his Ars Magna Lucis 

 et Umbrse, under the heading " On a certain wonderful wood, color- 

 ing water all kinds of colors." (Op. cit., p. 77.) He calls attention 

 to the fact that other writers before him had described the wood as 

 coloring water only a blue color ; yet in his experiments he had found 

 that it transformed Avater into all kinds of colors. His description 

 of the plant yielding the wood was not made from observation but 

 was undoubtedly taken from Ximenez's translation of Hernandez's 

 work, published 31 years previously. He then goes on to say: 



The wood of the tree thus described, when made into a cup, tinges water when 

 poured into it at first a deep blue, the color of a Bugloss flower ; and the 

 longer the water stands in it the deeper the color it assumes. If then the 

 water is poured into a glass globe and held against the light, no vestige of the 

 blue color will be seen, but it will appear to observers like pure clean spring 

 water, limpid and clear. But if you move this glass phial toward a more 

 shady place the liquid will assume a most delightful greenness, and if to a still 

 more shady place, a reddish color ; and thus it will change color in a marvelous 

 way according to the nature of its background. In the dark, however, or in an 

 opaque vase, it will once more assume its blue color. 



Kircher announces that he was the first to observe this chameleon- 

 like color, as far as he knew, in a cup given to him as a present by the 

 procurator of the Society of Jesus in Mexico. This cup he after- 

 Avards sent as a gift to his Sacred Majesty the Emperor, as something 

 rare and little known. " But," he adds, " as to the cause of the 

 strange phenomenon which I observed, I failed at first to understand 

 it; for I saw that the color could be counted neither among the 

 apparent nor the true colors; not among the former, because the true 

 or real color comes from the nature of the wood and not from the 

 light variously modified, as is usual with apparent colors ; nor can it 

 be considered a real color, since no color is seen in it when it is held 

 up against the light; and it assumes different kinds of colors only 

 when held against different objects." The learned philosopher, true 

 to his boast that there was no problem in nature that he could not 

 solve, concludes with the statement : " Taught, however, by various 

 experiments, I have at last found the cause, which I shall publish 

 hereafter." This, however, he never did. 



Four years after the publication of Kircher's work Johan Bauhin, 

 in his Historia Plantarum (1650), describes a second cup made of 

 Lignum nephriticiom, which he had received under the name of 

 PcduTn indianum from a colleague, Dr. Schopffius, physician to the 

 Duke of Wiirtemberg. This ingeniously made cup, almost a span 

 in diameter and of no common beauty, resulting from the variegated 

 18618°— SM 1915 IS 



