July 9,1870.] 
THE PHARMACEUTICAL JOURNAL. 
25 
or 2-25 oz. of dry matter per head of the population. 
The washings of streets have been carefully examined 
by Professor Way, who finds that the liquid discharged 
into the gullies, after a heavy shower of rain, contains, 
in the case of granite roads, about 813 3 grs. of solid 
matter per gallon, and of this 276-2 grs. are dissolved, 
and 537-1 grs. suspended. In that of wood pavements 
it contains only about 39 grs. per gallon, of which 34 
grs. are dissolved and 5 grs. suspended. The general 
average of the washings of several streets differently 
paved, and with various amounts of traffic, gave 262-6 
grs. of solid matter per gallon, of which 113-3 grs. were 
dissolved, and 149 - 3 grs. suspended. The refuse of fac¬ 
tories, etc., cannot be easily determined, and therefore 
we are obliged to rely for our results on the second 
method of investigation—namely, the analysis of the 
sewage at different times and places. 
In this metropolis the sewage discharged by day con¬ 
tains about 94 grs. of solid matter per gallon, of which 
38 grs. are suspended, and 56 grs. dissolved: of the sus¬ 
pended matters, 17 grs. are organic, and 21 grs. mineral; 
and of the dissolved, 15 grs. are organic, and 41 grs. 
mineral. The night sewage is not so rich in solid 
elements, for it contains only, about 79 grs. of solid mat¬ 
ter per gallon, of which 14 grs. are suspended and 64 
grs. dissolved ; and of these, 15 grs. are organic, and 64 
mineral—the organic being distributed very evenly be¬ 
tween the soluble and insoluble constituents. 
Branch sewers, and those which are nearly stagnant, 
are generally very foul, for the sewage of them contains 
from 150 grs. to 500 grs. of solid matter per gallon, of 
which from 90 grs. to 250 grs. are suspended. The 
organic matter ranges from 20 grs. to 120 grs. in the 
soluble part, and from 20 grs. to 176 grs. in the in¬ 
soluble. 
Taking- the average of all the results obtained in the 
examination of the metropolitan sewage by Dr. Hofmann, 
Mr. Witt, Professor Way, and myself, it may be said 
that it contains about 90-4 grs. of solid matter per gallon, 
of which about 29-8 grs. are suspended, and 60-fi grs. 
dissolved, there being about 15 grs. of organic matter in 
■each of these constituents. 
A storm of rain does not diminish the proportion of 
solid matter, for although it has a tendency to dilute 
the sewage, yet it washes away so large a quantity of 
filth from the streets, and disturbs so much of the sedi¬ 
ment in the stagnant sewers, that the sewage after a 
storm generally contains more than the average propor¬ 
tion of solid impurity. Taking 90 grs. per gallon as the 
usual amount, it will be increased after a storm to 125 
grs. per gallon, of which 64 grs. are suspended, and 61 
grs. dissolved. 
' The physical properties of sewage are peculiar, for 
when examined under the microscope the clear liquor is 
found to contain a large quantity of •amorphous organic 
matter, with filaments of various fungi, and it swarms 
with the lower forms of animal life, as beaded spirulina, 
vibriones , and monads ; but soon after exposure to the air 
higher forms of infusoria appear, as paramecium, vorticella , 
rotifera , etc. The sedimentary matter consists of the 
remains of undigested food, as muscular fibre, husk and 
hail- of wheat, the cells and starch of potato, and the 
tissues of vegetables, as cotton, cabbage, etc., and fibres 
of wool. It also contains the products of some of the 
secretions, as yellow biliary matter, intestinal mucus, 
and crystals of uric acid and triple phosphate; besides 
the debris of the streets, as particles of granite, flint, and 
•carbonate of lime, with a large quantity of black amor¬ 
phous matter. 
[To be continued.) 
THE “ABC” PROCESS F$>R THE TREATMENT 
OF SEWAGE. 
This process of purification, which has boen adopted 
at Leicester and also on the south coast, at Hastings, 
and which is sometimes called “Sillar’s process,” was 
patented by Messrs. W. C. and R. G-. Sillar, and W. G-. 
Wigner. The process is described in the specification 
of the patent as follows:— 
“We add to the sewage to be purified a mixture con¬ 
sisting of the following ingredients:—Alum, blood, clay, 
magnesia or one of its compounds, by preference the 
carbonate or the sulphate, manganate of potash, or other 
compoimd of manganese, burnt clay, otherwise known 
as ballast, chloride of sodium, animal charcoal, vegetable 
charcoal, and magnesian limestone. Of these substances, 
the. manganese compound, the burnt clay, chloride of 
sodium, and magnesian limestone may be omitted, and it 
is not essential that both animal and vegetable charcoal 
should be used. If any of the ingredients named should 
from any cause be present in sufficient quantity in the 
sewage, it may, of course, be omitted from the mixture. 
The proportions in which the ingredients are to be used 
vary according to the nature of the sewage to be purified, 
as, for instance, if a large proportion of urine is present, 
we increase the proportion of clay; if the sewage is much 
diluted, we slightly increase the proportion of alum and 
blood; if it contains a large proportion of street refuse, 
we decrease the proportion of clay. 
“For ordinary sewage the following proportions have 
answered well:— 
Alum . 
Blood. 
3 3 
Clay. 
Magnesia. 
5 
33 
Manganate of potash . 
. 10 
33 
Burnt clay .... 
. 25 
33 * 
Chloride of sodium 
10 
33 
Animal charcoal . . 
. 15 
33 
Vegetable charcoal . . 
. 20 
33 
Magnesian limestone . 
2 
» 
“These substances are mixed together and added to 
the sewage to be purified until a further addition pro¬ 
duces no further precipitate. The quantity required will 
be about four pounds of the mixture to one thousand 
gallons of sewage. In many cases it is preferable to 
mix the above compound with a small quantity of water, 
and add it in a liquid state to the sewage. The sewage 
must then be thoroughly mixed with the compound, 
and allowed to flow into settling tanks. The greater 
part of the organic and other impurities will be imme¬ 
diately separated in the form of large flakes, which 
rapidly fall to the bottom, leaving the supernatant water 
clear and inodorous, or nearly so. The water may then 
be allowed to flow away into a river, or be disposed of 
in any other way, and the sediment or mud allowed to 
accumulate at the bottom of the tank. In some cases it 
is preferable to add the compound of manganese to the 
water after the sediment produced by the other in¬ 
gredients has been allowed to subside. The sediment 
will be found to possess the power of precipitating a 
further quantity of sewage; it must therefore be pumped 
or otherwise taken from the tank, and mixed with fresh 
sewage, the sediment being allowed to subside in the 
same way as before. The sediment may be used five or 
six times over in this way. When the sediment no 
longer possesses the power of precipitating the impurities 
in the sewage, it must be removed from the tank and 
allowed to dry; when partially dry a small quantity of 
acid, by preference sulphuric acid, may be mixed with 
it, which will retain all the ammonia in a soluble form. 
When dried, the sediment will be a valuable manure.” 
THE ECLECTIC INHALER. 
This apparatus, which is made by Maw and Son for 
Messrs. Bullock and Reynolds, is described in the follow¬ 
ing terms by Dr. Morell Mackenzie, by whom it appears 
to have been designed. 
