523 Prof. A. H. Church on certain Ethylphosphates, [Dec. 8, 



the water- oven, it retains one atom of water of crystallization, and has the 

 formula Hj Agj P0^ + Aq. It was chiefly by double decomposition with 

 the barium, lead, and silver salts that the compounds presently to be 

 described were formed. The perfect purity of the substances used was 

 established by rigorous experiment ; a silver- determination, for instance, in 

 the argentic ethylphosphate used in many of the reactions to be detailed 

 further on, gave the following numbers : — 



10-27 grains of the salt dried at 100° C. gave 8*22 grains of AgCl. 

 This result corresponds to 60' 24 per cent of Ag, while the percentage 

 required by the formula H,, Ag2, P0^ + Aq is 60*33. The other analyses 

 were equally satisfactory. 



I give, in the present communication, a selection of the most interesting 

 of the numerous results obtained during the course of my experimental 

 inquiry. Many points of departure for other researches have occurred — 

 the investigation, for example, of the products, volatile and fixed, of the 

 destructive distillation of the ethylphosphates, and the determination of the 

 varying amount of water of crystallization in several of the salts prepared. 

 I may cite the barium salts as illustrations. Not only do the salts already 

 mentioned exist, namely one containing 6 Aq and the other 1 Aq, but a third 

 compound may be obtained by evaporating at about 50° or 60° C. a saturated 

 solution of the ordinary barium salt, and filtering off the deposited crystals 

 rapidly. The slender pearly plates thus formed are perfectly definite and 

 constant in composition ; they probably consist of equal equivalents of the 

 two former salts. Analysis gave the following numbers : — 

 7*04 grains gave 5*01 grains of Ba^ SO^. 



12*88 grains lost at 130° C. 2*5 grains of 0. 



These results correspond to 41*85 per cent, of Ba, and 19*407 per cent, 

 of O ; the formula 2 (C^ Ba^ POJ-f- 7 Aq demands 42*28 per cent, of 

 Ba, and 19*44 per cent, of HjO. 



Ferric Ethylphosphate. — Equivalent proportions of argentic ethylphos- 

 phate and pure crystallized anhydrous ferric chloride were weighed out. 

 The silver salt was mixed with some quantity of hot water, and the ferric 

 chloride, previously dissolved in hot water, then added, the liquid being 

 kept warm for some time. On filtering, a pale yellow liquid was obtained 

 which contained no silver, and the merest trace of chlorine. On heating 

 this liquid to the boiling-point, pale straw-yellow films separated from it : 

 a quantity of these was collected, washed with cold water and with alcohol, 

 and, after having been dried in the water-oven, analyzed with the following 

 results : — 



I. '6115 grm. of the ferric salt gave on combustion with chromate of 



lead -296 grm. of CO, and -22 grm. of H^O. 

 II. '475 grm. gave -142 grm. of Fe^ O3. 



III. -393 grm. gave * 1 1 5 grm. of Fe^ O3. 



IV. -475 grm. gave '294 grm. of Mg^ O^. 



V. 1*317 grm. lost at 150° C. -134 grm. of H^O. 



