286 Mr. T. E. Thorpe on the [Feb. 17, 



this compound, I solidified the chloride in a freezing-mixture of ice and 

 salt, allowed it to melt partially, and poured away the liquid portion. 

 This operation was repeated several times in order to remove any tri- 

 chloride which might possibly be present. The boiling-point of the 

 chloride was, however, unaltered by this treatment ; the liquid distilled 

 completely between 107° and 107 o, 5, the greater portion boiling at 

 107 o, 30, under a pressure of 751 millims. Corrected and reduced boil- 

 ing-point 107°-23. 



A second preparation made by G-erhardt's method, i. e. by heating phos- 

 phorus pentachloride with crystallized boric acid, boiled at 107 o, 4, under 

 a pressure of 765 millims. Corrected boiling-point 107 o, 22. 

 The first sample was analyzed with the following results : — 



I. "Weight of POCl 3 in vacuo 1-3156 gram. 



Weight of AgCl „ 3-6907 grams. 



II. Weight of POCI3 „ 1-4364 gram. 



Weight of AgCl „ 4-1064 grams. 



Found. 



Calculated. , * N 



I. II. 



Chlorine 69-36 per cent. 69-37 69-39 



Three determinations of specific gravity made with different bottles 

 gave the following numbers : — 



1 1-71185 



II 1-71189 



III 1-71182 



Mean 1-71185 at 0° 



compared with water at same temperature ; compared with water at 4° 

 the specific gravity is 1-71163. 



The rate of expansion of phosphoryl trichloride from 0° to its boiling- 

 point may be accurately represented by the expression 



7=1 + 0-001 064309^+0-000 001 126 66? 

 + 0-000 000 005 299* 3 . 

 By means of this formula the following Table, showing the true volume 

 of phosphoryl trichloride at every 10° between 0° and 110°, has been cal- 

 culated: — 



°c. 



Yolume. 



Diff. 



°c. 



Volume. 



Diff. 







100000 





70 



108184 



1278 



10 



101076 



1076 



80 



109507 



1323 



20 



102178 



1102 



90 



110878 



1371 



30 



103309 



1131 



100 



112300 



1422 



40 



104471 



1162 



110 



113776 



1476 



50 



105669 



1198 









60 



106906 



1237 



107-23 



1-133615 





