52 Prof. T. E. Thorpo on the History of the 



solid matter, agree closely with the determinations of later 

 analysts*. The total volume of the dissolved gases in the 

 imperial gallon was estimated by Dr. Hunter at 34 cubic inches, 

 and by Mr. West at 36*4 cubic inches. 



The true chemical history of the spring may, however, bo 

 said to date from Dr. Hofmann's analysis, , made nearly a 

 quarter of a century ago f. His examination first made known 

 with certainty the proper nature and proportion of the consti- 

 tuents of the water ; it is therefore only since 1853 that we can 

 determine with accuracy the character and extent of the changes 

 which have taken place. The existence of barium and stron- 

 tium in the water was first stated by Mr. Hayton Davis in 

 1866 |; he has since made a number of observations;, extend- 

 ing over the year 1872, to determine the effect of the seasons 

 on the spring § . An analysis was also made by the late Dr. 

 Muspratt in 1867 ||. In the main his results agree closely 

 with those of Dr. Hofmann. 



The water, the analysis of which forms the main subject of 

 the present communication, was collected in the early part of 

 August 1875. When drawn from the well it was perfectly 

 clear and colourless, smellecl strongly of sulphuretted hydro- 

 gen, and had a decided alkaline reaction. When shaken it 

 formed small pearly bubbles, and in a few hours became tur- 

 bid from the separation of sulphur. After standing for some 

 time it again became clear and acquired a faint yellow tinge ; 

 this change, which occurs more rapidly on warming with free 

 exposure to air, is due to the formation of an alkaline bisul- 

 phide. The rate of the flow of the spring was estimated at 

 30 gallons in the hour. The temperature of the water at the 

 time of collection was 10° C. (50° F.) ; in April 1876 it was 

 8° C. (46° # 5 F.). Mr. Davis has already noticed similar vari- 

 ations ; according to his observations its mean temperature 

 in 1872 was 9°«4 C. (48°-9 F.). Dr. Hofmann in 1853 ob- 

 served 9° C. (48°'2 F.). Dr. Walker in 1783 also observed 

 48° F. 



The specific gravity of the water at 16 0, 8 C, compared with 

 distilled water at the same temperature, was 101 1*04; this 

 number agrees closely with the observations of Dr. Hofmann 

 and Mr. Davis. 



The following substances were found to be present in deter- 



* Treatise on the Mineral Waters of Harrogate, &c. By Adam 

 Hunter, M.D. (1830). 



t " Chemical Analysis of the Medicinal Waters of Harrogate," Journ. 

 Chem. Soc. vol. vii. p. 161. 



X Chem. News, 1866. § Journ. Chem. Soc. 1873. 



