1865.] Double Chlorides and Oxalates. 151 



Experiments. I. II. Theory. 



Oxalate of strontium 54-03 54-22 54'15 



Chloride of strontium 16-44 16-51 16-31 



Water, fixed at 100 C 7*77 7'40 7'39 



Water, given off at 100 C. .. 21-76 21-87 22-15 



100-00 100-00 100-00 



With respect to the mode in which the change of the first compound into 

 the second takes place under the circumstances above detailed, there is one 

 fact which it is necessary to mention, namely, that the solution of chloride 

 of strontium of the strength in which the prismatic crystals are formed 

 from the rhomboidal, and in which they can be kept unchanged, does not 

 affect the crystals of the simple oxalate. Hence it is evident that the 

 oxalate set free by the decomposition of the rhomboidal crystals by the 

 addition of only a small quantity of water, is, from the circumstance of its 

 being brought into contact with the dissolved chloride of strontium on the 

 instant of its formation, more easily acted upon by it than if it had before 

 been in a perfectly formed state. This is probably from the nascent parti- 

 cles not having assumed a decidedly solid form ; the chemical union would 

 not require to be preceded by the same process of mechanical disintegra- 

 tion as in the latter case. The subsequent processes of solution of the in- 

 cipient particles of the newly-formed salt, and their deposition in a crystal- 

 line form, admit of the same explanation as that already given in the case 

 of the microscopic process. 



As to the properties of the double salt of oxalate and chloride of calcium, 

 I may observe that this salt is acted upon by water similarly to that of the 

 oxalate and chloride of strontium, being instantly resolved into oxalate and 

 chloride by the sudden action of water in sufficient quantity. The action 

 of water applied gradually and in small quantity I have not sufficiently 

 examined to be able to give a process for the preparation of a second salt. 

 The salt is very slightly soluble in the solution in which it is formed, and 

 rather more so in the hot than in the cold solution. After all the solution 

 of chloride of calcium has been separated from it by means of blotting- 

 paper, or by means of ablution with absolute alcohol, it is not deliquescent 

 in an ordinary atmosphere. 



The following is the formula deduced by Mr. Tribe from the subjoined 

 analysis : 



a Ca a O 4 . 2Ca Cl . 2H a O. 5 Aq. 



Experiments. I. II. Theory. 



Calcium 21-88 21-88 21-92 



Oxalic acid 23'67 23*67 24-11 



Chlorine 19'40 19'44 19'45 



Water, fixed at 100 C 10'36 10-14 9'86 



Water, given off at 100 C. .. 24'69 2474 24'66 



100-00 100-00 100-00 



