VOL. XLVI.] PHILOSOPHICAL TRANSACTIONS, C8Q 



where they prepare sulphur and vitriol. Carlsbad is a small town, situated in a 

 hollow between 2 high mountains : a small river called Toeple runs through it 

 from s. E. to N. w. The principal fountain rises on the north-east side, about 

 20 paces from the river, and about 5 or 6 feet higher than the surface of the 

 water. This spring rises through a square tube of wood, of about 7 inches dia- 

 meter, with a considerable degree of violence : whence it is called the sproudle, 

 or furious fountain. It comes from the mountain on the other side, and passes 

 underneath the river, where the petrifying quality of its owm water has formed 

 for itself an aqueduct of tophus, through which it is conducted to this place. 

 Sometimes this aqueduct is so filled and choaked up with the tophus, that it 

 bursts into the river, and puts the inhabitants to a considerable expence for re- 

 pairing it. But to prevent this, they bore and clean it every year near the foun- 

 tain. It forms rocks of tophus along the river side, composed of strata of se- 

 veral colours, according as the water has been impregnated with different matter, 

 or perhaps from the difference of heat or cold, or the impressions of the air at 

 the times of forming the lamellae. This tophus is hard, and receives a good 

 polish, and of it they make snuff boxes, heads of canes, and other toys. 



On the other side of the river, at the foot of the mountain, are a good many 

 houses, and a broad street ; cross under which the stream runs, and in the winter 

 no snow lies on the place where it passes. Some rooms in a house built here 

 are always warm like a bagnio, and in one of the cellars may be heard the noise 

 of the water running under ground. Along this side of the river are several hot 

 springs, which differ in quality from one another, as well as from the water of 

 the sproudle. The principal of these is called the mill-fountain, which is much 

 used, and reckoned milder than the sproudle. It is not near so saturated with 

 the limy matter, and forms scarcely any tophus. The sproudle is so full of the 

 stony matter, that any thing laid into it is covered over with a thick tophus in a 

 few days. When the water is taken up, and let stand a little in the air, it in- 

 crusts the vessels that contain it, and its surface is covered with a scale, like 

 lime water, which is made use of as a dentifrice. 



Most of the rocks about Carlsbad are an aggregate of spatum, mica, quartzum, 

 rubrica, cum matrice lapidis calcarei, and cleave into rhomboids. The soil on 

 the side of the mountain is made by the dissolution of such rocks intermixed 

 with some vegetable earth ; and the whole surface is covered with the least dis- 

 solvable parts, often adhering together in masses by the intervention of a limy 

 matter like incrusted spatum, and he found higher up the mountain some rocks 

 mouldering into such soil. The Carlsbad waters give a good deal of neutral 

 salt by boiling and ci7stallizing. From 1080 lb. of water 22 oz. of pure salt. 

 His thermometer being broken, he procured one of a friend : but not knowing of 

 what construction it was, he tried it in the following manner: in melting ice the 



VOL. IX. AT 



