DAVIS ON THE ANCIENT ALUM WELL AT HARROGATE. 19 111.-The Ancient Alum Well at Harrogate. By R. HAYTON DAVIS F.C.S. DR. THOMAS GARNETT a physician in practice at Harrogate in the year 1791 and afterwards Professor of Chemistry at the Royal Institution, London in his treatise on “ The Mineral Waters of Harrogate,” mote as follows :-“ In one of the sulphur wells situated in the bog I have discovered alum and I suspect salited clay. In a chalybeate water near the road, and not far from the Crescent garden the iron is dissobed by the mnriatic acid.” Dr. Adam Ilunter a physician resident in Leeds in his book entitled “ The Waters of Harrogate and its Vicinity,” published in 1830 commenting upon these st:ttements says :-“ The reader will I believe look in vain for alum or muriate of iron in the waters referred to.” The discovery of ferrous chloride in! 1865 in one of the Zrrrogate Spas near the site indicated by Dr.Garnett and the substance of my paper this evening strongly support Dr. Garnett’s observations. So far back as 1733 lk. Thomas Short of Sheffield B.R.S. mentions an alum well in the bog-field at Harrogate describing its position the nature uf the ground and the experiments he made with the water. DT. Garnett referring to these observations says :-‘‘ From Dr. Short’s experiments it seems to have been a chalybeate water in which the iron is held in solution by the sdphuric acid;” then he adds “ I have found two or three springs of this kind in the bog very near some sulphur wells.” Since Dr. Garnett’s residence in Harrogate a period of 80 years elapsed and the existence of the alum well passed quite out of memory.It was not until 1870 when excavations were made in the bog-field €or the purpose of increasing the supply of sulphur-water that this aluminous water again came to light ; the excavation was afterwards deepened earthenware pipes were put down forming a well about 4 feet deep and 14 inches diameter where the water slowly collects. c 20 DAVIS ON THE ANCIENT ALUM WELL AT HARROOATE. This aluminous water is of a pale reddish-brown colour strongly acid to litmus and very astringent taste; after keeping a short time if Jxposed to the air a portion of the iron is precipitated as basic aul-phate and the protosulphate gradually changes into the ferric salt. The ground in its vicinity is strongly acid to litmus tastes austere, even after heavy and continuous rains ; depressions in the ground after a shower more particularly in summer are found filled with water corresponding in colour and taste with that in the well.Imniediately under the peaty soil in various places around the well there is a layer of deposit having a sulphur-yellow colour ; its appear-ance has no doubt given rise to the statements of Dr. Short and other old writers respecting the prodigious quantities of sulphur to be found in the locality. I find on examination it contains about 60 per cent. soluble in hydrochloric acid consisting of SO3 1460 FeaOt 29-82 Snd small quantities of Ca Mg Na &c. ; it bears a remarkable resemblance to two of the ferruginous deposits found in the neighbourhood of the Caspian Sea the analyses of which by A.Frenzel are published in the September number of the Journal of this Society. To revert to the alum well its position is remarkable in being almost surrounded by sulphur wells which circumstance together with the surface of the soil being so strongly impregnated with the con-stituents of the water strengthens the opinion that the water is of comparatively superficid origin and is continually produced by natural causes. The old deposits from the chalybeate waters situate on higher ground and the sulphur waters rising through the stratum of shale at a lower level appear to be the factors in the production of this remark-able water. The Ancient Alzlm Well at Harrogate. The Quantities are irt Graiflzs per Gallon. Xp. gr. 1OC3.43. Fe 47.59 Ferric sulphate. . Mg 11.47 Calcium ,. K . . 1.40 Magnesium , NH 0.59 Ammonium , SOa 265.44 Sodium chloride Cl 20.60 Silica SiO 3.27 394.70 A1 1424 Ferrous snlphate Ca 16-74 Aluminium sulphate ??a 13.36 Potassium , Total residue dried 360-380" 397.25 78.76 69.33 89.47 56-91 57.38 3.14 2-19 33.96 3.27 394.4