598 

NATURE 
[May 5, 1923 

Letters to the Editor. 
[The Editor does not hold himself responsible for 
opinions expressed by his correspondents. Neither 
can he undertake to return, nor to correspond with 
the writers of, rejected manuscripts intended for 
this or any other part of NAVURE. No notice ts 
taken of anonymous communications. | 
Hafnium and New Zealand Sand. 
THE account which was given in NarureE of Feb- 
ruary I0 (p. 195) of the very refractory substance 
which I obtained from a black titaniferous iron sand 
from New Zealand and believed to be the oxide of 
the newly discovered element, hafnium, requires now 
to be brought up-to-date. In that account it was 
mentioned that I had sent to Copenhagen practically 
all my purified material for X-ray examination and 
comparison with the preparations and specimens of 
the discoverers. Three specimens were sent: (a) the 
sand itself, (b) the cream-coloured substance labelled 
in 1918 “‘ New Oxide,” (c) the cinnamon-coloured 
oxide which resulted from the atomic weight deter- 
minations (Chem. Soc. Jour. for February, p. 312). 
The total amount of (b) and (c) was between 0-3 and 
0-4 gram each and was all I had. The result of the 
first examination by Drs. Coster and Hevesy was to 
the effect that they were unable by X-ray spectral 
analysis to detect hafnium in any of the three speci- 
mens, and this I announced at the meeting of the 
Chemical Society on February 15. 
Drs. Coster and Hevesy very kindly undertook a 
much more thorough and laborious examination, both 
by X-ray and by optical spectral analysis, especially 
of (c), which was naturally regarded as the purest 
sample of the oxide. They did this in the hope of 
finding some evidence of the presence of some of the 
other elements still missing, and in particular element 
No. 75, but in this they were unsuccessful. Their 
final report is that ‘‘ The chief components are un- 
doubtedly iron and titanium ’”’ with traces of man- 
ganese, aluminium and magnesium. As soon as I 
received this statement on March 1g I set to work on 
what remained of (b) and (c) to try to unravel the 
mystery of the high atomic weight which had seemed 
to prove conclusively that the oxide was that of an 
element with an atomic weight at least one and a 
half to two times that of zirconium (90-6). As the 
full analytical details and the steps by which the 
explanation was arrived at are given in the Journal 
of the Chemical Society for April, p. 881, I need not 
do more here than give the general conclusions. My 
further chemical examination of the cinnamon-coloured 
powder (c) agrees entirely with that of Drs. Coster 
and Hevesy in proving that it consists practically of 
oxides of titanium and iron, the latter only to the 
extent of about half a per cent. It is to the presence 
of this iron oxide that the cinnamon colour is un- 
doubtedly due. 
The “‘ New Oxide”’ (b), however, seems to be a 
new oxide so far as chemical literature is concerned, 
but not the oxide of a new element. Further in- 
vestigation showed it to contain a large percentage 
of silicon and that, so far as could be ascertained 
with the small quantity which I had, there seems to 
be but little doubt that it is a form of titanium 
dioxide in which part of the titanium is replaced by 
silicon. It is due in all probability to this replace- 
ment of titanium by silicon that the ‘“‘ New Oxide ”’ 
owes its resistance to the attack of sodium bisulphate 
on one hand and caustic soda on the other. 
The substance extracted from a New Zealand sand 
(while my specimens were in Copenhagen) by Dr. 
NO. 2792, VOL. 111 | 


C. J. Smithells and Mr. F. S. Goucher (NATURE, March 
24, Pp. 397) in the Research Laboratories of the General 
Electric Company, is entirely different from my “‘ New 
Oxide.’ This is clearly proved by their own state- 
ments; hence their experiments with it have no 
bearing on the composition and properties of the 
substance isolated by me. : 
I gladly avail myself of this opportunity of acknow- 
ledging and thanking Prof. Bohr and Drs. Coster and 
Hevesy for all their courtesy and for the very great 
trouble they have taken to assist me in the elucida- 
tion of what seemed to be a real mystery. It is with 
sincere pleasure that I have just learned that they 
have succeeded in the difficult task of preparing 
hafnium compounds in a state of purity sufficient to 
enable them to locate its atomic weight between 179 
and 181. ALEXANDER SCOTT. 
34 Upper Hamilton Terrace, 
London, N.W.8, 
April 25. 
A Meteorological Disturbance of an Oscillatory 
Character. , 
A DISTURBANCE possessing a pronounced oscillatory 
character swept across the Gulf of St. Vincent, South 
Australia, on the morning of February 24. It may 
be of interest to put upon record its chief features. 
At 5.10 A.M. those who were sleeping out of doors 
were rudely awakened after a stifling airless night 
(wind N.N.E., strength o-1) by a sharp westerly 
squall. A lull was succeeded by a second squall 
about 7 minutes after the first ; a well-marked line- 
cloud accompanied it, but no rain fell. The wind 
then dropped to a gentle S. breeze for a few minutes, 
but the approach of another splendidly developed 
line-cloud arching the horizon from S.S.E. to N.N.W. 
heralded another squall from the west. The upper 
atmosphere was almost cloudless, save on the western 
horizon, where an alto-cumulus layer drifted slowly 
from a northerly point. Again the wind went round 
to the S. and dropped, but a third line-cloud brought 
a fresh squall from the west. 
The writer, observing from Glenelg, faced forty 
miles of sea stretching out to the westward, and it 
was a very fine sight to watch the unbroken lines of 
cloud, 2000 to 3000 feet up, approaching at a very 
great speed and stirring up an almost calm sea into 
momentary activity. The three clouds passed over 
within the space of a quarter of an hour, and were 
separated by approximately equal intervals of time. 
The wind which accompanied them was not very 
violent, probably between 30 and 40 miles an hour, 
but strong enough to cause the anchored yachts to 
swing round through go° from S. to W. in a few 
seconds. : 
Though no further line-clouds were observed, the 
oscillatory character of the disturbance continued, 
and at two further intervals of 8 and 7 minutes 
respectively the squalls and vagaries of the shipping 
were noted. Eye observations were then suspended, 
but the writer is indebted to Mr. Bromley, Common- 
wealth Meteorologist for the State of South Australia, 
for traces of the automatic records obtained at 
Adelaide, 6 miles inland and E. of Glenelg, which 
. 
i 
. 
a | 
| 
show that the pulsations continued for about an hour 
altogether. The periodicity is especially well-marked — 
in the barograph and wind velocity curves repro-— 
duced below; at first they keep remarkably in step, 
each rise in the barometer coinciding with an increase 
in wind velocity and vice versa, but there is some con- — 
fusion in the velocity graph towards the end of the 
disturbance. : 
suspicion of furnishing low readings, but it is also 
The anemo-biagraph has been under ~ 
