510 safford: lignum nephriticum 



an indication of alkalinity in all cases. As compared with 

 phenolphthalein it has a neutral point nearer the acid end of the 

 scale; that is to say, it will fluoresce in a solution in which phenol- 

 phthalein develops no color whatever. 



FURTHER BOTANICAL HISTORY 



As already stated, the first description of the plant yielding 

 lignum nephriticum is that of Hernandez, written about the year 

 1575, but first published in the form of a Spanish translation, 

 in the city of Mexico, by Ximenez, in 1615. It is as follows: 



They call coatl a plant which they describe as a shrub ; but I have seen 

 it larger than very large trees; and some call it tlapalezpatli, or "blood- 

 red medicine." It is a large shrub which has a thick trunk devoid of 

 knots, like that of a pear tree. The leaves are like those of the gar- 

 vanzo [Cicer arietinum], but smaller and almost like those of rue [Ruta 

 chalepensis L.] and somewhat larger, a mean between these two extremes; 

 the flowers yellow and faded, small and longish, are arranged in spikes. 



. . . It grows in moderately warm regions like the valley of 

 Mexico, and in still warmer situations like Guachinango [state of 

 Puebla], Chimalhuacan [district of Texcoco], Chalco, and Tepuztlan 

 [near Cuernavaca, state of Morelos] and almost throughout the entire 

 extent of the malpais [pedregal or lava-beds] of Coyohuacan; and in 

 many other places. 



■ Following Monardes, whose description of the wood he quotes, 

 the author tells of the blue color of the infusion of the wood and 

 of its virtues as a diuretic; and he adds: ''There is another kind 

 of plant of this nature, but it does not color the water;" and on 

 his return trip to Spain he says: ''In this fleet there is a Viscayan 

 merchant who is taking more than fifty large logs of this wood 

 to Spain." 



From the above description it is evident that Hernandez refers 

 to two distinct species, the first of which, with leaves resembling 

 those of Cicer arietinum and Ruta chalepensis and with spikes of 

 small longish flowers, is undoubtedly Eysenhardtia polystachya, 

 which never exceeds the size of a small tree. It was undoubtedly 

 the wood of this species which Robert Boyle used in making his 

 experiments on fluorescence. The second is in all probability 

 one of the trees called by the Aztecs tlapalezpatli, or tlapaliz- 

 patli (from tlapalli, tincture; eztli, blood; and patli, medicine), 



