Oct. 20, 1875] 
NATURE 
sample of the demi-area of which it forms the central strip 5 
neither is it at the moment of observation in the same condition 
as when it passed over us. Precisely the same may be added in 
respect to the six hours of weather which are the subject of pre- 
diction, It must also be especially borne in mind that whatever 
error may affect the twelve-hour average is necessarily doubled in 
the six-hourly prediction, because the difference between what 
was expected of the whole twelve hours, and what has been 
fulfilled in the first half of it, must be heaped on to the second 
half, which has therefore to bear an additional load of error, 
equal in amount to its rightful share. Thus, if 100 miles of 
wind had been expected, and eighty miles really came, in the 
twelve hours, the error of the expectation would be one in four ; 
but if forty miles of wind had come in the first six hours, the 
prediction would assign sixty miles to the next six hours, whereas 
the fact would show forty miles, making an error in the predic- 
tion-of two in four, or double the original error of expectation 
for the whole twelve hours. 
SEcTION B.—CHEMICAL SCIENCE 
On the Utilisation of Sewage, with Special Reference to the Phas- 
phate Process. —Mr. David Forbes, F.R.S. &c. The processes 
at present employed for the treatment of sewage were classed 
under two heads: the purely mechanical and the mechanico- 
chemical, The former, which at best only effected a mere 
filtration of the sewage, have everywhere failed to effect any 
such purification of the sewage water as was necessary in order 
that it might be allowed to flow directly into the streams. Sewage 
irrigation was included in the latter class, not because any direct 
chemical treatment was employed, but for the reason that, whilst 
the soil acted mechanically as a filter to separate the solids, the 
chemical action exerted by the vegetation decomposed and assi- 
milated the organic matter, ammonia, and other available 
substances in the liquids also. The more purely chemical p:o- 
cesses, such as the treatment by lime alone, or in combination 
with chloride of iron, alum, sulphate of alumina, and, lastly, the 
so-called A B C process, were next alluded to, but regarded as 
failures, since the evidence brought forward not only proved that 
the affluent water had not been sufficiently purified, but also that 
the sewage manure obtained was, by the admixture of the materials 
employed in these processes, rendered of so low an agricultural 
value as to preclude its employment elsewhere than in the im- 
mediate neighbourhood of the sewage works. 
Admitting that sewage irrigation was to be recommended wher- 
ever the local circumstances were favourable to its employment, it 
was maintained that under many circumstancesit was neither appli- 
cable nor advantageous, and that in these cases it was preferable 
to employ a chemical treatment, which had the advantage of not 
requiring any large outlay for pumping or distributing machinery, 
or the purciase of large areas of ground for sewage farms. For 
this purpose an entirely new process was recommended, called 
the phosphate process, based on the property which hydrated 
phosphates have of combining with organic matter, whilst the 
ammonia also can be precipitated in the condition of the double 
phosphate of ammonia and magnesia. 
The prcec2ss was shown experimentally with Liverpool sewage, 
and consisted merely of adding a solution of certain phosphates, 
chiefly of alumina, in sulphuric or hydrochloric acid to the 
sewage, and afterwards a little milk of lime barely sufficient to 
neutralise the acid and give a faint alkaline reaction to the sewage ; 
even if tinctorial matters of great intensity (ink was added in the 
experiments) were present, the liquor became immediately dis- 
coloured, the supernatant liquor resting quite clear above a pre- 
cipitate of the phosphates along with all the insoluble matter and 
a large portion of the soluble organic matter and ammonia ori- 
ginally contained in the sewage. The authors of this process, 
Messrs. A. Price and D. Forbes, although they did not pretend 
to have extracted the entire amount of the ammonia and 
other matter valuable for agriculture from the sewage, 
or to effect an absolute purification of the affluent water, 
believed that, as the water so purified was free from any 
nauseous taste, so that it could be drunk without repug- 
nance, was devoid of smell, and did not putrefy or emit any 
disagreeable odour even when left standing in an open vessel 
during the whole of the preceding hot summer, that it had been 
sufficently purified by the phosphate process as to permit of its 
being directly vun off into rivers without detriment to the fish in 
them or the health of the inhabitants on their banks. 
503 
A most particular feature of this process when compared with 
the other processes of precipitation was, that the substances em- 
ployed in effecting this purification were not detrimental to the 
agricultural value of the precipitated manure, but, on the con- 
trary, added so much to its value as to enable it to bear the cost 
of transport to distant parts of the country, and thus showed 
some hope that the value of the manure might be sufficient to 
pay for the expense of treating the sewage. 
SECTION C,—GEOLOGY 
Remarks on newer Tertiary Fossils in Sicily and Calabria. 
Mr. J. Gwyn Jeflreys, F.R.S. In the last deep-sea ex- 
ploring expedition in H.M.S. Porcupine, in the Bay of Biscay, 
and along the Atlantic coasts of Spain and Portugal, Mr. 
Jefiveys procured at considerable depths, and especially from 
994 fathoms, many species of mollusca in a living or recent 
state, some of which had previously been regarded as fossil only, 
and extinct, and all as belonging to the newer tertiaries of Sicily 
and Calabria ; and he believed that a record of the fact might 
lead to the further discovery of the geological phenomena which 
had caused the fossilisation of such species in that limited area. 
Several of these species inhabit northern, and even Arctic, seas ; 
such are Terebvatula cranium, &c. Other species now found ina 
living or recent state, are Zerebratula spheroidea, &c. One of 
the last species, in the last list or category (ifaresepla papillesa) 
was also dredged by Mr. Jeffreys last autumn, at Drobak, in 
Norway ; and he was of opinion that our knowledge of the 
Arctic marine fauna was very imperfect. The newer Tertiary 
fossils of Sicily and Calabria had been to a great extent investi- 
gated by Dr. Philippi, formerly of Cassel, Professor Seguera of Mes- 
sina, the Abbé Brognone of Palermo, and Dr. Tiberi of Resina 
near Naples; and their collections had been examined by Mr, 
Jeffreys. Two s.iggestions or questions were submitted by the 
author ofthe present paper. 1. Havenotall the deep-sea species 
of European mollusca originated inthe north, and spread south- 
wards in consequence of the great Arctic current? 2, Inas- 
much as the pliocene division of the Tertiary formation is now as- 
certained to contain scarcely any extinct species, and the future ex- 
plorations may reduce the percentage of such species to w//, may 
not that artificial division hereafter merge in the quaternary 
formation, and the tertiaries be restricted to eocene, miocene, and 
pliocene ? 
The President and Sir Roderick Murchison spoke of the great 
importance of this communication, and the latter hoped Mr. 
Jeffreys did not share the opinion of his colleague Dr. Carpenter, 
that their discoveries tended to upset modern geology. 
Professor Duncan confirmed Mr. Jeffreys’ statement with 
respect to the specific identity of corals from deep-water with 
those of the South-Italian tertiaries. 
The Rev. H. W. Crosskey also addressed the Section as to the 
glacial fossils of Scotland being quaternary and not tertiary. 
Mr. Jeffreys, in reply, begged to assure Sir Roderick, as one 
of the parents of English geology, that he need not be under 
any apprehension for his offspring, so faras the deep-sea explo- 
rations were concerned. 
Modern and Ancient Beaches of Portland.—Mr. W. Pengelly. 
The Chesil Bank having been described, the author stated that he 
had found amongst the flints of which it was chiefly composed, 
specimens of Budleigh Salterton pebbles, some containing the fos- 
sils occurring in these pebbles. Somegranite pebbles were probably 
from the valley of the Teign. From these specimens it was con- 
cluded that the transportation along the coasts of South Devon 
and South-west Dorset is up Channel, that is, in the direction of 
the prevalent winds. The Raised Beach of Portland Bill con- 
sists of 7 feet of yellow clay, the same of pebbles, sand and shells 
from the Raised Geach, and 50 feet of rock resting at sea-level on 
ashingle beach. The shells are species now living on the shore. 
The beach was held to indicate an elevation of the coast of not 
less than 50 feet ; and the pebbles showed that at the time of 
their deposition the direction of transportation was the same as 
now. Portland was then an island. 
On the Occurrence of Seams of Hard Sandstone in Middle Drift 
of Last Anglia. —Mc. J. E. Taylor. This sandstone was composed 
of 66 per cent. of siliceous sand, cemented by 33 per cent. of 
carbonate of lime. It occurs immediately below the upper or 
chalky boulder-clay. Formerly it was employed at Norwich in 
building, the Castle being built of it. Even in beds later than 
the boulder-clay, specimens of indurated sandstones had been 
found by the author, proving, as he believed, that the older rocks 
