278 ANNUAL EEPORT SMITHSONIAN INSTITUTION, 1915. 



The last author to investigate the origin of ligninn nephriticiim is 

 Dr. Hans-Jacob Moller, of Copenhagen, who, after an exhaustive 

 study of the subject, referred it to a Mexican tree belonging to the 

 genus Pterocarpus. Dr. Moller made a careful examination of the 

 various woods hitherto supposed to be the true lignum nephriticimi 

 mexieamuTn, among them specimens of the wood of Eysenhardtia 

 amorpTioides sent to him by C. A. Purpus — the latter described as 

 "das Kernholz von einem recht dicken Ast" — ^but with negative 

 results {^'' heine Fluoreszenz'''') . On examining the heartwood of 

 a Philippine species of Pterocarpus, however, he found that in water 

 containing lime it yielded an infusion having the characteristic sky- 

 blue fluorescence of lignum nephriticum described by early investiga- 

 tors. He therefore assumes that the mother plant of lignum 

 nephriticum, mexicanum^ " sought in vain for 300 years by so many 

 investigators is a Mexican species of Pterocarpus," in all probability 

 Pterocarpus am^phymenium DC. {Amphymennim pubescens H. B. 

 K., Pterocarpus pubescens Sprengel) ; and he refers a second kind 

 mentioned by Hernandez, endemic in Quauhchinango, to Pterocarpus 

 orhiculatus DC.^ 



TWO DISTINCT SOURCES OF THE WOOD. 



In these attempts to trace lignum nephriticum to a single mother 

 plant the writers have been confronted with serious difficulties. How 

 could Eysenluirdtla polystachya^ a shrub or small tree, be its origin, 

 when, according to Plernandez, logs of lignum nephriticum of great 

 size were transported to Spain. And how could the wood of this 

 species, with its dark-colored heart and yellow infusion, be identi- 

 fied with the " white " woods of Monardes and Kircher yielding an 

 infusion as white and clear as spring water, or with the wood of 

 Johan Bauhin with its variegated lines and its red sawdust? And, 

 if lignum nephriticum originated in Mexico, w^hy has the long search 

 in that country for cups made of it been unavailing? On the other 

 hand, it may be asked. How could the mother plant of lignum nephri- 

 ticum be a species of Pterocarpus if, as Hernandez writes, its com- 

 pound leaves are composed of minute leaflets suggesting those of 

 Cicer arletinum or the ultimate divisions of the leaves of Ruta chale- 

 pensisf 



Figure 1 shows a leaf of Humboldt and Bonpland's original type 

 plant of Pterocarpus pubescens {Pt. afmphymerium DC), to which 



1 Moller, Hans-Jacob. Lignum nephriticum. Berichte der Deutsclien Pharmaz. Gesellsch. 

 23: 88-154. 1913. 



