394 



INDEX. 



Pithecolobium Palmeri, Hemsl., 272. 



var. recurvum, 272. 



Plants, Mexican, some new species of, 



chiefly of Mr. C. G. Pringle's 



collection in the mountains of 



Chihuahua, in 1887, 268. 



Plants of Guatemala, descriptions of 



some, 283. 

 Plants of the United States, some new 

 species of, with revisions of 

 Lesquerella (Vesicaria) and 

 of the North American species 

 of Draba, 249. 

 Platinum, on the existence of certain 

 elements, together with the 

 discovery of, in the sun, 14. 

 apparatus used, 14. 

 method of working, 15. 

 results of experiments : — 

 bismuth, 18. 

 cadmium, 17. 



cerium, molybdenum, urani- 

 um, and vanadium, 17. 

 lead, 17 

 lithium, 18. 

 platinum, 19. 

 potassium, 18. 

 silver, 18. 

 tin, 18. 

 Pleurothallis Blaisdellii, 284. 

 Biigbami, 285. 

 Choconiana, 285. 

 minutiflora, 280. 

 Plumbic B- brorn - 8 -sulphopyromu- 

 cate, 198. 

 /3y-dibrom-5-sulphopyromucate, 



202. 

 B - sulpho - S - brompyromucate, 



209. 

 S-sulphopyromucate, 191. 

 Polemonium pauciflorum, 280. 

 Polypetalous genera and orders, notes 



upon some, 



99;- 



Potassic aa - dibromf urf uran - B - sul- 

 phonate, 211. 

 /3y-dibrom-S-sulphopyromucate, 



203. 

 8 - sulpho - S - brompyromucate, 



210. 

 /3-sulphopyromucate, 217. 

 S-sulphopyromucate, 192. 

 Potassium in the sun, 18. 

 Potentilla Pringlei, 272. 

 Prionosciadium, 275. 

 Madrense, 275. 

 Mexicanum, 275. 



Prionosciadium Pringlei, 276. 



Priva Orizabae, 282. 



Proceedings, 305. 



Ptelea, 224. 



Pyromucic acids, on substituted, 188. 



Pyrus occidentalis, 263. 



R. 



Report of the Council, 315. 



Rotala Mexicana, Cham. & Schlecht., 



273. 

 Rotch, Abbott Lawrence, election of, 



311. 

 Rutacese, 223. 



S. 



Sabazia glabra, 277. 

 Sanvitalia tenuis, 277. 

 Saxifraga occidentalis, 264. 

 Scaphyglottis longicaulis, 286. 

 Schkuhria Pringlei, 278. 

 Sedum Chihuahuense, 273. 



Madrense, 273. 



Pringlei, 273. 



puberulum, 273. 

 Senecio Chihuahuensis, 280. 



umbraculifera, 279. 

 Sicyos minimus, 274. 

 Sidlacea Hendersoni, 262. 

 Siegesbeckia orientalis, Linn., 277. 

 Silene Luisana, 261. 



Pringlei, 269. 

 Silicon, fluoride of, the action of, on 

 organic bases, 20. 



on aniline, products of, 21. 



on other bases, 27. 



constitution of the silicotetraflu- 

 orides, 32. 

 Silicotetrafluoride, dianiline, 26. 



didimethylamine, 31. 



dipyridine, 122. 

 Silicotetrafluorides, constitution of 



the, 32. 

 Silicotetrafluorides of certain bases, 



122. 

 Silver in the sun, 18. 

 Sodic S-sulphopyromucate, 192. 

 Spectra, metallic, wave-lengths of, in 

 the ultra violet, 288. 



apparatus, 292. 



conclusions, 297. 



