July 23, 1370.] 
THE PHARMACEUTICAL JOURNAL AND TRANSACTIONS. 
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SATURDAY, JULY 23, 1S70. 
THE RULE OF THUMB. 
In another part of this week’s Journal will be 
found a set of specimens illustrative of the worldng 
of the Rule of Thumb. Each powder in six packets 
of patent medicines was weighed, and the weights 
showed a variation in quantity of from one to about 
two ; the practical effect of this irregularity being, 
that the patient, when he takes a powder from a 
packet of such a medicine, will take half a grain or 
one grain of calomel, or something intermediate 
between these quantities, just as chance may favour 
him. It is a lesson to use the balance, and not to 
guess at quantities. Nothing is more delusive than 
the eye as a measure of the weight of powders. A 
practised eye will one day be strangely successful in 
making such valuations, and another day as strangely 
unsuccessful. 
THE SEWAGE QUESTION. 
The public interest is at present so deeply involved 
in the determination of an efficient remedy for the 
sewage nuisance, to which so large an amount of 
j;iver pollution is due, and the “A. B. C.” method has 
been so confidently advocated for the purpose, that 
the Royal Commissioners on River Pollution have 
considered it their duty again to submit this method 
to careful investigation. Though the results of their 
previous observations were objected to by the pa¬ 
tentees, they did not admit the validity of the ob¬ 
jections, and the results of further inquiry given in 
the Report, just presented to Parliament, fully con¬ 
firms the unfavourable opinion previously expressed 
as to the efficiency of the A. B. C. method. 
The following are the general conclusions arrived 
at by the Commissioners:— 
“1. The process removes a large proportion of the sus¬ 
pended impurities from sewage, but on no occasion, when 
we have seen it in operation, has this removal been so 
complete as to render the effluent sewage admissible into 
running water. 
“ 2. The ‘ A. B. C.’ process removes a very small pro¬ 
portion of the soluble polluting matters from sewage. 
After treatment by this process, the effluent sewage is 
very little better than that which is obtained by allow¬ 
ing raw sewage to settle in subsidence tanks. 
“3. The manure obtained by this process has a very 
low market value, and cannot repay the cost of manu¬ 
facture. 
“ The manipulations required for the extraction and 
drying of this manure are attended with a nauseous 
gdour, especially in warm weather, and would occasion 
a serious nuisance if the works were situated in or near 
a town. 
“ It would obviously be rash to set any bounds to the 
possibilities of chemistry. Substances may, perhaps, be 
hereafter discovered capable of combining with and ren¬ 
dering insoluble the filthy constituents of our town 
drainage; but we are compelled to admit that the pre¬ 
sent resources of this science hold out no hope that the 
foul matters dissolved in sewage will be precipitated and 
got rid of by the application of chemicals to the offen¬ 
sive liquid. The chemical affinities of these foul mat¬ 
ters arc so feeble, and the matters themselves are dis¬ 
solved in such enormous volumes of water, that their 
precipitation is a problem of extreme difficulty.” 
The Commissioners add that the inevitable con¬ 
clusion from their inquiry is unfavourable to the 
A. B. C. method in respect of its alleged power to 
hinder the pollution of rivers by town sewage, and 
that it is equally unfavourable as to the value of the 
manure manufactured by this method. The one 
statement is indeed in some sense the complement 
of the other; for just in proportion as the impuri¬ 
ties of sewage escape separation, so must the value 
of the manure obtained from it be reduced. 
It is interesting to note in reference to the impor¬ 
tant question as to the value of the A. B. C. manure, 
that “artificial fortification ” is occasionally practised. 
It appears that during a recent visit to the works at 
Leamington by Dr. Miller and Dr. Odling, crystals 
of sulphate of ammonia were discovered in the ma¬ 
nure that was being made. 
There are also other points in Dr. Odling’s evi¬ 
dence before the Royal Commissioners, which throw 
a very dubious light on this matter. 
Dr. Letheby’s paper on the subject, which is 
completed in this number, is hi reality little more 
than an admission that sewage can be defecated by 
irrigation, and its contents utilized to some extent 
at least, while his argument against this mode of 
dealing with sewage simply amounts to the very ob¬ 
vious assertion that it must be properly conducted. 
This is a truism that few would dispute. It is re¬ 
markable that most of those who took part in the 
discussion declared the subject to be outside their 
province. Even among the opponents of irrigation 
there was little accord, for while Mr. Hawksley be¬ 
lieved there was. nothing to be learned, and Dr. 
Letheby asserted that medical men were alone com¬ 
petent to decide the matter, Dr. Cobbold regarded it 
as chiefly one for chemists to deal with. Moreover, 
in reference to the pollution of rivers by effluent 
water, Dr. Letheby’s advocacy of precipitation me¬ 
thods, which remove so little of the impurity from 
sewage, is glaringly inconsistent with his assertion 
that they were preferable to irrigation, which has 
been proved to purify sewage to much greater ex¬ 
tent, and for that reason offers a better prospect of 
utilization when properly conducted. 
A prop os of sewage, we learn from the ‘ Medical 
Times and Gazette,’ that some members of the un¬ 
fortunate British Association Committee have laid 
their troubles before the Council of the Association, 
stating in reference to the protest entered against their 
proceedings- with the money subscribed by towns, 
that they felt it would be unbecoming in them and 
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