WATER ANALYSIS A HUNDRED YEARS AGO. 143 



somewhat more of a brown reddish mass. If, however, a glass 

 retort is made use of, and the water is drawn off by a very gentle 

 sand heat with great circumspection, almost a third more may be 

 gained from the same quantity of the water. The salt, which 

 is afterwards extracted from the insoluble residuum, is in the 

 proportion of 10 gr. (of the former) to 2 of the latter. This salt, 

 when mixed with spirit of vitriol, causes a very considerable 

 ebullition, affording thereby essential evidence of its alkaline 

 quality, in addition to what has already been observed. When 

 this salt is rubbed with sal ammoniac it has an urinous pungent 

 smell, and when it is mixed with salt of tartar it gives off rather 

 an offensive foetid odour." 



" It has been observed that a very pretty experiment may be 

 made with this water after being kept a proper time, and this 

 without the trouble of a regular chemical process [such, I suppose, 

 as the writer has already indicated]. By keeping the Nottington 

 water in bottles for the space of a twelve-month, or more, it affords 

 a spontaneous partial analysis of itself; light bodies of different 

 colours are observed floating on its surface. These are the sul- 

 phureous particles now all collected together, which were originally 

 diffused throughout the substance of the whole. These slender 

 corpuscules, if carefully taken up and dried, and afterwards strewed 

 on a red-hot poker or bar of iron, flame and sparkle beautifully into 

 an infinite variety of colours, resembling a peacock's tail, very 

 elegantly illustrating the formation of the variegated scum so 

 frequently observed on the surface of many mineral waters, 

 sulphureous as well as chalybeate." 



It seems that Dr. Crane was not the first in the field, but that 

 he had been preceded by Godfrey in 1719. by Dr. W. Gumming, 

 of Dorchester, in 1740, and by Dr. Rutty in 1749. Their experi- 

 ments were even more elaborate than his own, the reagents used 

 being solutions of silver, lead, copperas, and alum, sea-water, soap, 

 volatile alkalies (mild and caustic), tincture and powder of galls and 

 such other astringents, syrup of violets, &c. The results obtained 

 are not stated, but they are. supposed to " tend indisputably to 



