82 Reriews— Geological Survey of Basingstoke. 
Recently examining a specimen of uranite (autunite), I was struck 
by its resemblance to the artificially prepared uranium salts, and it 
occurred to me that in all probability it would be found to exhibit the 
spontaneous luminosity observed in these by H. Becquerel,’ which is 
attributable to fluorescence of the substance under the action of its 
own radio-activity. Experiment confirmed this anticipation. The 
mineral is: easily perceived in a perfectly dark room by a well-rested 
eye. There is no difficulty in walking up to it from a distance and 
touching it, without any other guidance than the luminosity. Autunite 
is more luminous than uranium nitrate, but less so than potassium 
uranyl sulphate. 
This effect is quite independent of the previous exposure to light. 
Such exposure only leaves an afterglow in uranium salts of very 
short duration. It cannot be detected without the phosphoroscope. 
The specimens in which I have observed the luminosity are some 
recently raised in Portugal, which I owe to the kindness of Mr. A. de 
Vere Hunt. Old specimens from Cornwall and from Autun do not 
exhibit it. The loss of luminosity is connected with a loss of water of 
erystallization. This was established experimentally by sealing up 
a specimen in an exhausted glass tube with phosphoric anhydride. 
In a few hours the latter had deliquesced considerably, while the 
autunite had lost both its luminosity in the dark, and also the green 
fluorescent. shimmer which it had previously exhibited in daylight. 
Some uranium salts are known to be much more fluorescent than 
others, and there is nothing specially surprising in the fact that a loss 
of water is accompanied by a loss of brilliancy. 
RAV LEWwSs-. 
pois ee 
'J.—Geronogican Survey or Grear Brrrarw. 
Tus Grorocy or run Counrry around Bastnesroxn. By, Ee ad 
Ossorne Wauire, F.G.S. pp. v, 119, with 14 text-illustrations. 
1909. Price 2s. Colour-printed map, Sheet 284, 1s. 6d. 
LTHOUGH not officially connected with the Geological Survey, 
ue Mr. Osborne White has already rendered much service to the 
Institution in writing the Memoir on the Geology of Hungerford and 
Newbury, and in assisting with those on Andover, Henley-on-Thames, 
and Wallingford. He has now written the memoir to accompany 
Sheet 284 of the new series Geological Survey Map, which embraces 
an area concerning which we have hitherto had very little detailed 
information beyond that contained in previous official memoirs on 
more extensive tracts, by H. W. Bristow, W. Whitaker, and A. J. 
Jukes-Browne. The six-inch field-maps, showing the revised geology, 
with notes by the late J. H. Blake and Messrs. C. E. Hawkins and 
F. J. Bennett, were placed at the service of the author, 
The country under consideration is almost wholly in Hampshire, 
the northern part including a tract of the Eocene strata of the London 
Basin ; and the southern part consisting mainly of Chalk with a portion 
' Comptes Rendus, 1904, vol. 138, p. 184. 
