standley: north American species of genipa 639 



the salt was added and allowed to stand over night before filter- 

 ing. The precipitates obtained were weighed, fused with sodium 

 carbonate, leached with water, and filtered. To determine zir- 

 conium the insoluble residue was fused with sodium bisulphate, 

 and the melt was dissolved in water, precipitated with ammonia, 

 filtered, and the zirconium weighed as oxide. The phosphorus 

 in the leach water was determined as MgoPcOv after preliminary 

 precipitation as phospho-ammonium molybdate. Repeated tests 

 of the leach water for sulphates showed that the precipitation of 

 the phosphate did not carry down sulphate. 



As both iron and titanium may be thrown down with zirconium 

 phosphate it is desirable to use a solution containing the greatest 

 possible quantity of free acid, and the titanium must be kept 

 well oxidized with hydrogen peroxide in order to prevent it from 

 being precipitated. 



Other phosphates than zirconium phosphate, except those of 

 the rare earth metals, are readily soluble and may be easily 

 separated in dilute acid solutions. 



It is not safe to base definite conclusion on the results of work 

 involving quantities so small as those used in these experiments, 

 but those results indicate the formation of a basic salt that ap- 

 proaches normal zirconium phosphate as the acidity of the solu- 

 tion is increased. The table given indicates that the solution 

 employed may safely contain at least 3 per cent and perhaps as 

 much as 5 per cent of free sulphuric acid. 



BOTANY. — The North American species of Genipa.^ Paul C. 

 Standley, National Museum. 



The genus Genipa is a member of the family Rubiaceae, tribe 

 Gardenieae, being closely related to the genera Gardenia and 

 Randia. About 15 species are known, most of them American 

 (chiefly South American), although several have been described 

 from the tropics of the Old World. From North America 3 

 species of the genus have been reported heretofore, Genipa amer- 

 icana L., G. caruto H. B. K., and G. codonocalyx Standi. Genipa 



' Published with the permission of the Secretary of the Smithsonian Institu- 

 tion. 



