APRIL 14, 1904] 
NATURE 
599 
collapse on the part of modern men of science? The 
explanation offered is simple; it is merely that they 
have learned their method from ‘‘ that unfortunate 
being J. S. Mill. I consider the authority of J. S. Mill, 
and the fact that his ‘Logic’ and  ‘ Political 
Economy ’ were and still are text-books in the Uni- 
versity of Oxford, to be a national disaster, and almost 
equivalent to destroying English intelligence in the 
germ.’’ Most of the opinions here advanced are of 
equal weight with the foregoing. 
We have let the author of this elegantly printed book- 
let speak for himself. He abounds in humour both 
of the conscious and unconscious variety, the latter 
predominating. EAS D: 
Bray and Environs. (Bray, Ireland: Published and 
Sold by Arthur L. Doran, 1903.) Price 1s. net. 
Mr. Doran has produced a cheerful and original little | 
guide to the gateway of the Wicklow highlands, and 
devotes five pages to the botany, geology, and orni- 
thology of the district. -In the botanical part he relies 
on the careful work of Mr. R. Lloyd Praeger (‘‘ Irish 
Topographical Botany ’’), published by the Royal Irish 
Academy, but he does not seem to have utilised the 
admirable new memoir to the Dublin area, prepared 
by Mr. Lamplugh and his colleagues, when drawing 
up his geological notes. This Geological Survey pub- 
lication, including Killiney and many of the places 
mentioned, should be referred to in the next edition. 
Messrs. Ussher and Warren may then also appear as 
authorities in the section on the Irish birds. 
But the present book is distinctly attractive, and full 
of quaintly expressed ideas. Anyone who reads the 
quotations from the Venerable Bede and Dr. Raverty, 
the medical superintendent officer of health, set in 
juxtaposition on p. 5, cannot fail to seek further, confi- 
dent that he is in pleasant hands. Some of the refer- 
ences owe their sparkle to a touch of irony, such as 
the unkind mention on p. 11 of Mr. Evans and his 
votive offerings. Apropos of this, the holy well in 
Mr. Barrington’s land in co. Dublin, with its twentieth 
century offerings of rags, is mentioned quite naturally 
on p. 35. Archzologists will note a profound signifi- 
cance in the very simplicity of Mr. Doran’s words, 
and will, it is to be hoped, visit the old-world valley 
with no other feeling than respect. The present writer 
was once guided there in the gathering dusk, when 
Dublin, ten miles distant, seemed to lie, by another 
measure, thirty centuries away. 
The mention of this obscure well, and of the little 
used but singularly picturesque route round Carrick- 
gollogan (p. 89), will serve to show the perceptive 
spirit in,which Mr. Doran has written for the tourist. 
Gea. 
Senior Country Reader. Ill. By H. B. M. 
Buchanan, B.A. Pp. viiit+293; with 143 illustra- 
tions. (London: Macmillan and Co., Ltd., 1904.) 
Price 2s. 
An enthusiastic reception may be predicted for this 
volume on the part of boys and girls in rural schools 
who have studied Mr. Buchanan’s previous books in 
this series. There is a surprising amount of inform- 
ation provided, but it is generally presented in a 
sufficiently interesting manner to avoid weariness on 
the part of the young reader. The subjects treated— 
such as manuring, crops, cottage gardens, pigs and 
poultry—are just those which engage the practical 
attention of the children out of school, and about which | 
they must know something after leaving school. It 
is clear from the beginning that Mr. Buchanan writes 
from personal experience in agricultural pursuits, and 
this fact will inspire the confidence of the student, 
while the numerous good illustrations will make quite 
clear what is being described. 
NO. 1798, VOL. 69] 
LETTERS BO” THE EDITOR. 
(The Editor does not hold himself responsible for opinions 
expressed by his correspondents. Neither can he undertake 
to return, or to correspond with the writers of, rejected 
manuscripts intended for this or any other part of NATURE. 
No notice is taken of anonymous communications.] 
A New Mineral from Ceylon. 
SINCE writing last week, I have made further experiments 
on the cubical mineral, and have myself carefully examined 
the earth constituents. The statement made last week, that 
there is only an insignificant amount of thorium present, 
must be modified. On re-determining the equivalent of the 
crude oxalate, prepared after the yttrium metals had been 
separated by treatment with potassium sulphate, it has come 
out higher than I expected; indeed, assuming the metal 
present to be a tetrad, its atomic weight is even higher 
than that of thorium—about 240, as the mean of two closely 
| concordant determinations. The lower equivalents men- 
tioned in the previous letter were determined as fractions 
of the double potassium sulphate, prepared on a large scale. 
This high atomic weight points to the presence of unknown 
elements of higher atomic weight than thorium; indeed, 
the mineral appears to be of very complex composition. 
It may be incidentally remarked that the crude oxalate 
mentioned above must have contained all the cerium group, 
and if any considerable proportion of the elements of this 
group is present, the amount of the element with higher 
atomic weight than that of thorium would have to be pro- 
portionately increased. The high radio-activity would point 
to the presence of the elements obtained from thorium 
residues mentioned ‘by Prof. Baskerville, which he states 
to be radio-active. 
The equivalent was determined by comparing the weight 
of oxide from a known weight of oxalate with the percentage 
of oxalic acid, as determined by titration of another sample 
of the same preparation. Witiiam Ramsay. 
Tue letter dealing with the composition of a new mineral 
from Ceylon contributed by Sir W. Ramsay to Nature of 
April 7 (p- 533) reveals certain discrepancies between the 
analytical results obtained with this material at University 
College and those of the Scientific and Technical 
Department of the Imperial Institute recorded in Prof. 
Dunstan’s letter on this subject (March 31, p. 510). Sir 
W. Ramsay’s results indicate that this mineral is practically 
free from thoria, whereas those recorded by Prof. Dunstan 
show that it is particularly rich in this oxide. As Prof. 
Dunstan is at present abroad, and therefore unable at the 
moment to comment on Sir W. Ramsay’s letter, I may 
be permitted to direct attention to two observations men- 
tioned by Sir W. Ramsay, which appear to be open to 
question. 
He states that the oxalate obtained from a_ solution 
of the mineral is soluble in excess of a solution of 
ammonium oxalate, and that this reaction excludes the 
presence of thorium or metals of the cerium group, and 
points to the presence of zirconium. This inference is not 
in harmony with the observation recorded by Bahr (Annalen, 
1864, 132, 231), that thorium oxalate is soluble in excess 
of ammonium oxalate, a fact since confirmed by Bunsen 
and by Brauner (Journ. Chem. Soc., 1898, 73, 951): 
Further, the solubility of the thorium salt in excess of 
ammonium oxalate has been used by Hintz and Weber 
(Zeit. Anal. Chem., 1897, 36, 27) and by Glaser (ibid., p- 
213) as a method of separating thoria from monazite and 
similar minerals. It would appear, therefore, that the 
principal. evidence brought forward by Sir W. Ramsay in 
support of his conclusion that the mineral contains no 
thoria in reality supports Prof. Dunstan’s statement that 
it is rich in this oxide. It may be added that the solubility 
of the oxalate obtained from the mineral in ammonium 
oxalate had already been observed in this Department. 
Sir W. Ramsay appears to be of opinion that the principal 
constituent of the mineral is the oxide of a new tetravalent 
element with an equivalent of about 447- If this were the 
case the specific gravity of the mineral would probably be 
j less than 8-2, whereas the determinations of this constant 
