Mar. 25. 1854.] 



NOTES AND QUERIES. 



283 



and although it is but a slight modification of Mr. 

 Ltte's process described in " N. & Q.," it is a very- 

 important one, and will be found to produce far better 

 results. The picture having been developed in the usual 

 way, with a solution of pyrogallic acid, is whitened by 

 means of Mr. Archer's solution of bichloride of mer- 

 cury. The plate is then washed with water and a 

 solution of iodide of cadmium poured on. This con- 

 verts the white chloride of mercury, which constitutes 

 the picture, into the yellow iodide, in the same manner 

 as the solution of iodide of potassium recommended by 

 Mr. Lyte ; but is much to be preferred, as it pro- 

 duces a more uniform deposit. The solution of iodide 

 of potassium dissolves the iodide of mercury as soon as 

 it is formed, and therefore cannot be left on the plate 

 until the decomposition of the chloride is complete, 

 without injury resulting to the picture, as the half- 

 tones are thereby lost, and those parts over which the 

 solution first flows become bleached before the other 

 parts have attained their highest tone ; whereas the 

 solution of iodide of cadmium may be allowed to re- 

 main for any length of time on the plate, without any 

 fear of its injuring the negative. J. Leachman. 



Caution to Photographers. — About six months since, 

 I procured some gun cotton from a chemist which 

 appeared very good, being quite soluble, and the col- 

 lodion produced by it was excellent. That which I 

 did not use I placed in what I believed to be a clean 

 dry-stopped bottle, and put the bottle in a dark cup- 

 board. I was much surprised the other day, upon 

 going to the cupboard, to find the stopper blown out, 

 and the cotton giving out dense red fumes of nitrous 

 acid. It appears to me to be almost upon the point 

 of combustion, and I have, accordingly, placed it under 

 a bell-glass in a porcelain dish to watch the result. 

 I feel satisfied, however, that there is some risk, and, 

 as it may often be near ether, spirits of wine, or other 

 inflammable chemicals, that caution is necessary not 

 only in preserving it at home, but especially in its 

 transmission abroad, which is now done to some extent. 



An Amateur. 



HrpItoS ta fflinav &uerfe£. 



Artesian Wells (Vol. ix., p. 222.). — Wells are 

 often so called without just pretence to a similarity 

 with those in Artois, whence this name is derived. 

 There are some natural springs in the northern 

 slope of the chalk in Lincolnshire, near the | 

 Humber, called blow-wells, which may be const- j 

 dered naturally Artesian. The particular cha- J 

 racter by which an Artesian well may be known i 

 is, that the water, if admitted into a tube, will ! 

 rise above the level of the ground in its immediate j 

 vicinity up to the level of its sources in the basin j 

 of the district ; this basin being usually gravel, 

 lying betwixt two strata impervious to water, j 

 formed by the surrounding hills, and extending I 

 often over many miles of the earth's surface. If ! 

 we conceive the figure of a large bowl, inclosing a j 

 somewhat smaller one, the interstice being filled 

 with gravel, and the rain falling on the earth j 



j being collected within such interstice, then this 

 | interstice being tapped by boring a well, the water 

 j will rise up from the well to the same height as 

 it stands in the interstice, or rim of the natural 

 basin. Such is an Artesian well. Supposing this 

 huge mineral double bowl to be broken by a geo- 

 logical fault, the same hydrostatic principle will 

 act similarly. 



The question of preferable put by Stylites 

 ! must be governed by the cui bono. Universal 

 adoption is forbidden, first, by the absence of a 

 \ gravelly stratum betwixt two strata impervious to 

 water ; and secondly, by the excessive expense of 

 boring to such great depths. Where expense is 

 I not in excess of the object to be attained, and 

 where the district is geologically favourable, the 

 j Artesian wells are preferable to common ones de- 

 ■ rived from natural tanks or water caverns, first, 

 for the superabundant supply ; secondly, for the 

 ! height to which the water naturally rises above 

 ! the ground ; and thirdly, because boring Artesian 

 wells, properly so called, does not rob a neigh- 

 bour's well for your own benefit, afterwards to be 

 lost when any neighbour chooses to dig a little 

 deeper than you. This is a matter with which 

 London brewers are familiar. T. J. Buckton. 

 Lichfield. 



Prior's Epitaph on Himself (Vol. i., p. 482.). — 

 Mr. Singer quotes an epitaph on " John Carne- 

 gie," and says it is the prototype of Prior's epitaph 

 on himself. I have looked among Prior's poems 

 for this epitaph, and have not been able to dis- 

 cover anything that can be said to answer Mr. 

 Singer's description of it. Would your corre- 

 spondent oblige me with a copy of the epitaph to 

 which he alludes ? My edition of Prior is a very 

 old one ; and this may account for the omission, if 

 such it be. Henry H. Breen. 



St. Lucia. 



[The following is a copy of the epitaph: 



" Nobles and heralds, by your leave, 



Here lies what once was Matthew Prior, 

 The son of Adam and of Eve ; 



Can Bourbon or Nassau claim higher ? ""] 



Handwriting (Vol. viii., p. 639.). — In your 

 concluding Number of last year, E. B. requested 

 information as to any work in English, French, 

 German, or Spanish, giving a standard alphabet 

 for the various kinds of writing now in use, with 

 directions for teaching the same. I fear I shall 

 not satisfy all your correspondent's inquiries ; but 

 the following may be of some service. I have in 

 my possession a German work, nearly of the kind 

 he requires. The title is, Grundliche Anweisung 

 zum Schonschreiben, by Martin Schiissler, Wies- 

 baden, 1820. It is of an oblong shape, and con- 

 sists entirely of engraved plates, in number thirty- 

 two. It begins with some directions for the form 



