480 
DE. A. W. HOFMAXX OX THE PHOSPHOEUS-BASES. 
Li-iodate. — The base, neutralized with iodic acid and evaporated over sulphuric acid, 
yields an extremely deliquescent sjTup which crystallizes but gradually. Solution of 
potassa separates the hydrate from the concentrated solution, in oily drops, sparingly 
soluble crystalline iodate of potassium being at the same time precipitated. The solu- 
tion, mixed with hydrochloric acid, yields the lemon-yellow crystalline compound 
already mentioned. 
Carhonate. — The solution of the oxide remains alkaline, even after saturation "uith 
carbonic acid ; on evaporation, it leaves a mass ha^ing a slightly crystalline structure. 
Sulphate. — Radio-crystalline, extremely deliquescent salt. Repeated attempts to pro- 
duce diphosphonium-alums by mixing the solution "with the sulphates of aluminium and 
chromium were unsuccessful. 
Chromate. — The solution of the free base, neutralized with piu’e chromic acid, 
deposits, when in an atmosphere dried by sulphuric acid, extremely soluble needles 
arranged in stellated groups. With excess of chromic acid, nothing but an unciystal- 
lizable syrup is obtained. 
Oxalate. — Both the acid and the neutral solution of the base in oxalic acid dries rrp to 
a slightly crystalline mass. 
Phosphate. — The di-iodide, boiled with excess of phosphate of silver, yields a ireirtral 
solution of the phosphate of the diphosphonium, wirich remaiirs as a slightly crystalline 
mass when the solution is evaporated. Crystallization is irot promoted by addition 
either of free phosphoric acid or of the hydrate. 
Tartrate. — Extremely soluble ; difficult to crystallize. 
Dipicrate. — The aqueous solution of picric acid, added to a* moderately conceirtrated 
solution of the hydrate, instantly produces a yellow crystalline precipitate, wirich sepa- 
rates from the boiling alkaline solution hr long ireedles. 
The diphosphonium-salts form a long series of doirble compoirnds, irrost of wirich 
crystallize spleirdidly. 
Platinum-salt. — The solution of the dichloride, even wlreir extremely dilute, jields 
with dichloride of platinum a pale-yellow^ precipitate, wirich appears anrorplrous to 
ordinary observatiorr, but when examiired rrirder a nricroscope of rather high power, 
resolves itself into small prisms. This salt is ireaiiy insolirble in cold aird eveir iir 
boiling water, so that, as already observed, the diphosphoirium irray be quairtitatively 
estimated in this form. The precipitate dissolves, though with difficirlty, in coirceirtrated 
hydrochloric acid, and crystallizes from the solirtioir, by slow cooliirg, in small but well- 
defined crystals of a bright orange-red colour. 
Quintino Sella has examined these crystals, and obtaiired the followiirg results : — 
