358 



MR. T. CARNELLEY ON AN ANALYSIS OF 



The preceding is (I.) the analysis made of the water col- 

 lected by the author on September 8 th, 1874, together with 

 that (II.) made by Dr. Hassall in the early part of Septem- 

 ber 1 871*, or jnst three years previously. 



The following table represents the above in combination : 



Ferrous sulphate 



Aluminium sulphate 



Calcium sulphate 



Magnesium sulphate 



Potassium sulphate 



Sodium sulphate 



Lead sulphate 



Calcium chloride 



Sodium chloride 



Sodium nitrate 



Ammonium nitrate 



Aluminium phosphate 



Manganese 



Silica 



Albumenoid ammonia 



Bases for which there is not sufficient acid 



I. 



4090-4 



x 358 9 



922-3 

 670-3 



7°'3 



49'9 

 1-25 



19-4 

 4-8 



7-2 



3"2 



trace 

 157-0 

 o"34 

 '5'5 



7370-79 



II. 



5454*3 

 700-7 



376-0 

 2257 



47 'o 

 16-8 



trace 

 149-0 



1 -4 loss. 



6970-9 



With reference to this analysis the following observa- 

 tions are to be made : — 



(1) The determination of the total residue was first 

 made at 180 C. as recommended by Freseniusf; and the 

 result obtained corresponded to 800 parts per million; 

 it was founds however, that this was much too high, the 

 reason being that ferrous sulphate, though it loses six 

 molecules of water at 114 C, yet retains the seventh even 

 at 280 J. In order to drive off this remaining molecule, 

 the residue from 100 cub. cent, of water was heated in an 

 air bath to 300°-3io° and weighed; after repeated heating, 

 two successive weighings did not differ by more than a 

 milligramme. In heating to so high a temperature, how- 



* See 'Guide to Trefriw and Yale of Conway Spa,' by Dr. J. W. 

 Hay ward, M.D., M.R.C.S. Second edition. 



t Fresenius, ' Quantitative Analysis,' 4th edition, p. 560. 

 I Watts, ' Dictionary of Chemistry,' vol. v. p. 597. 



