416 
NATURE 
development of bacteria—a point that cannot be doubted—they 
may not kill the spores, thus permitting the germs of disease to 
escape. There are no experiments (of which I am aware) to 
answer this objection. But there is reason to believe that patho- 
genic germs do not resist for a very long time when in unfavour- 
able media; even in sewers, that are not over-filled and 
stagnant, and that are well ventilated, infection does not easily 
linger. If inside the sewers disinfection is complete, and 
bacterial growth checked, and all disease germs rendered in- 
active, until carried for away from all populous centres, I 
think we can leave it to air, and to the other natural agents, to 
ultimately destroy the surviving germs, or completely alternate 
their pathogenic qualities. 
Amongst the mineral acids, hydrochloric would, of course, be 
the cheapest. But I think sulphuric acid ought to be preferred, 
nitric acid being too costly and too corrosive. Sulphuric acid does 
not attack easily calcareous cements ; and if the sewers have their 
walls well plastered, the action of a s/igh¢ excess of sulphuric acid in 
the sewage would be very slight indeed. Cements, more resisting 
than plaster, could be prepared. Moreover, if some portions of teh 
sulphuric sewage get carried in the air, or are dried in the higher 
parts of the sewers, the germ-laden particles do not rid them- 
selves of the acid by evaporation; on the contrary, the acid 
becomes more concentrated and active, and finally must dis- 
organise and destroy the noxious germs. This is very important 
in preventing the effects of sewage air. 
Since 1881 Prof. Beilstein of St. Petersburg (NATURE, vol. 
xxiii. p. 394), experimentally concluded that sulphuric acid is 
the best disinfectant, although he did not advise its use because 
of its corrosive action. Strange to say, Beilstein thought that, 
practically, aluminous sulphate was to be preferred to the free 
acid, 
It is not only during the fear of cholera invasions, but at all 
times, that I would wish the sewage to be s/zg/t/y acidified with 
sulphuric acid. Strict supervision should be maintained over all 
the sewers, to ascertain that the whole mass of flowing sewage is 
permanently acid. I am persuaded that this simple mode of 
disinfection would diminish considerably many infectious 
diseases. 
During the cholera epidemic of 1884, in Naples, I did my 
best, in a series of letters I then published, to persuade the 
sanitary authorities of this mode of disinfection. But a strange 
confusion of ideas was then prevalent in Naples. Through the 
goodwill of Prof. Cantani, Member of the Sanitary Commission, 
some trials of the method I proposed were done, but not in a 
complete and systematic manner. Such experiments cannot be 
‘done easily in Naples, and the results cannot be conclusive until 
the system of sewers is in good working order. Indeed, insome 
parts of the soil of Naples it is difficult to know if there is more 
sewage inside or outside the sewers. It is no easy problem to 
disinfect and cleanse such an impure soil, and it is indeed to be 
wondered that the ravages of cholera were so limited in 1884. 
My letters caused sulphuric acid to be used abundantly in the | 
sewers and fo22t meri of Portici, Castellamare, Taranto, and, I 
believe, in other places; but this, like all other disinfections, 
was done under pressure of approaching cholera, and abandoned 
as soon as the danger passed, no observation being made to 
measure the influence of the sanitary method adopted on local 
infectious diseases. The defective system of sewers and of drain- 
age in many Italian towns renders thorough disinfection scarcely 
possible, and prevents precision in testing any kind of disin- 
fection. 
In English towns sewers are generally well arranged, and 
often well ventilated ; and vital statistics have taken sufficient 
development to permit the testing of sanitary reforms. When it 
is proved (and I think the proof can be easily given) that the 
present systems of sewage disinfection are not sufficient to prevent 
entirely bacterial development in the sewers, these systems cannot 
be considered good. I venture to hope that beneficial results 
would soon become evident if the sulphuric acid disinfection of 
sewage were thoroughly applied in English towns. 
Portici, August 20 ITALO GIGLIOLI 
Ozone at Sea 
THE presence of this element in the atmosphere is alleged to 
be indicative of its healthiness, and it has been zzvestigated on 
Zand frequently by observers with varying and uncertain results. 
Records of its presence may be seen daily in the Z7zmes, 
furnished from the Observatory on Ben Nevis, but as yet little 
notice has been taken of its prevalence at sea, though it has been 
supposed to be more plentiful there than on land. 
During a voyage around the United Kingdom on the s.s. 
Cey/on in August last, we entered into the investigation of its exist- 
ence at sea, and used Moffatt’s papers for the purpose, obtained 
from Negretti and Zambra. They were exposed in a perforated 
light wooden box, hung up in the open air on the deck of the 
ship in the shade, and noted and changed twice a day. 
It was found most prevalent in Coré Harbour (4), less so in 
Bantry Bay (2) and Oban Harbour (2), and nearly absent in 
Kingstown Harbour (1) and Leith Roads (1). 
In the open sea it was most shown in the /vish Channel (4) 
and off the Lands End (4) ; next in the North Seas (3) and in 
the English Channel (2), and least in the Irish seas (1) and 
western coasts of Scotland (1). 
Ozone was found to be indicated in greater intensity during 
the prevalence of wesferly winds in the English and Irish 
Channels, and Atlantic seas and Dutch seas, and less with 
easterly winds prevailing in the Irish seas, Firth of Forth, and 
west coasts of Scotland. 
The velocity of the winds seemed also to create a higher 
manifestation, as was seen during the gale from the south-west 
in Cork Harbour and the fresh north-westerly breezes on the 
south coasts of Ireland and east coasts of England. None, how- 
ever, of the observations approached those registered in the 
Times from Ben Nevis (8-9), which amounted to double those 
noticed in the seas around our coasts during the same period 
(August), supposing that the same papers and scale (Moffatt’s) 
were used for both sets of observations. 
Ozone was also found to exist in the cadin of the ship both day 
and night, but at a half intensity to that on the deck, due probably 
to the great difference in the movement of the air in the two 
places. 
The degrees of manifestation of ozone at sea here shown by 
no means$come up /o exfectation that it prevailed in all its 
potentiality on the ocean, but of course a whole year’s observa- 
tion would be required to enlighten the subject and furnish a 
comparison with that on the land. 
Again, it may be possible that a/¢itude may have something to 
do with its prevalence, more or less, as it appeared more on the 
top of Ben Nevis than on the level of the seas of the same coasts 
near it and at the same period of the year (August). 
Should this idea be of any significance it might be as well to 
search for manifestations of ozone at the base as well as on the 
top of mountains, and if similar results followed to these here 
pointed out it would establish the reputation of high level sites 
for great salubrity of atmosphere. W. J. BLACK 
August, 1885 
THE INTERNATIONAL BOTANICAL AND 
HORTICULTURAL CONGRESS, ANTWERP, 
1885 
7p Be International Botanical and Horticultural Con- 
gress met at Antwerp on Sunday, August 2, in the 
) hall of the Artistic, Literary and Scientific Club, the open- 
ing meeting being honoured by the presence of a good 
many ladies. The gathering was a representative one, 
and included many well-known European botanists and 
horticulturists. The Burgomaster of Antwerp opened the 
proceedings with a few appropriate remarks, and Prof. 
Ed. Morren, of Liége, having been made President of the 
Congress, took the chair, and a discussion was held on 
the flora of the Congo. After a short discussion the 
meeting adjourned to the Exhibition building, where the 
International Horticultural Show was being held, and 
which was formally opened at one o’clock. Many of the 
plants exhibited were of great interest, and the whole of 
the collections were nicely and artistically arranged. At 
five o’clock the Congress visited the Plantin Museum, the 
old printing office of the Plantin Moretus family. The 
Museum is full of interest, and as the printing office from 
which the works of Lobel, Dodonaeus, and Clusius issued, 
doubly interesting to all botanists. Through the kindness 
of the Burgomaster of Antwerp a sheet had been struck 
off for the members of the Congress, so that each was 
presented with a souvenir of the three great herbalists. 
[Sepd. 3, 1885. 
