72 
THE PHABMACEUTICAL JOUBNAL AND TBANSACTIONS. 
[July 23, 1870. 
should flow along two subsiding-tanks in series; the 
first should be capable of holding at least one hour s 
flow, and the second of holding not less than four hours 
flow. The tanks should be four deep in depth, and the 
overflow of the defecated sewage should be by a weir 
only half an inch below the surface. 
4. That there should be a double set of tanks for 
alternate working. 
5. That the defecated water should flow through _ a 
shallow open conduit of not less than a quarter of a mile 
in length before being received into a stream of freely 
running water, of not less than eight or ten times the 
volume of the defecated sewage. 
In this way, or by any similar method of defecation, 
the sewage of towns may be easily and safely dealt with, 
so as, on the one hand, to ensure its purification before 
it is discharged into a running stream, and, on the 
other, to avoid the many dangers of irrigation. 
I refrain from entering on the subject of the pecu¬ 
niary aspects of this question, for they are nowhere 
encouraging, notwithstanding that the most sanguine 
opinions have been expressed of the commercial and 
agricultural value of sewage. Irrigation, like precipita¬ 
tion, except in the case of the Leamington method, is 
everywhere unprofitable, when it is conducted in such a 
manner as to prevent the pollution of the neighbouring 
streams ; and I warn you against the glowing accounts 
which are given of the profitable returns of certain 
sewage farms, for, if the cost of outlay is considered and 
balanced with the average returns, it will always be 
found to be a losing affair. The most sanguine enthu¬ 
siasts have generally abandoned the system after a 
trial of its merits. Little or nothing, in fact,. can be 
profitably grown upon the sodden land but Italian rye¬ 
grass, and when this is abundant it must be cut, or it will 
rot upon the ground, and it must be sold for what it will 
fetch. In the summer of 1866, when I was in Edin¬ 
burgh, I saw acres upon acres of rye-grass rotting upon 
the far-famed Craigintinny meadows; and when I asked 
the cause of it I was told by the manager that the cattle 
plague had ruined his customers, and there_was nobody 
to buy it and nothing to eat, and there it must rot. 
Besides which, there are considerable doubts as to the 
value of it as fodder. Mr. Campbell, of Bugby, who 
ought to be a high authority on the subject,—for it was 
a pet of his,—honestly declares that his experience does 
not show a profit in the use of such fodder, and he gives 
a good example of it. Twelve Ayrshire cows, which 
calved about the same time, in May, 1869, yielded, at 
the end of twelve weeks, an average quantity of 91- 
quarts of milk per day per cow. Their daily consump¬ 
tion of rye-grass was cwt. per cow. If they had 
been milked for nine months, the average daily yield of 
milk would have been only from 5 to 6 quarts per cow. 
The cost of the grass, at 10s. a ton, was 9 d. per cow per 
day, and the other expenses of the dairy raised it to 
Is. 3 \d. per cow. The milk, at 8<7. per gallon, was 
worth only Is. 7 d., and when the cost of sending it to 
market was taken into account, together with the wear 
and tear of utensils, he vainly asked for profit. 
But all this is, as I have said, no part of my present 
inquiry, for my business is solely with the sanitary 
part of the question; and I would ask you whether, 
having regard for the public health, there are not serious 
clangers in the rash recommendations of the Boyal Pol¬ 
lution Commissioners to scatter the sewage of every city 
and town in the kingdom broadcast upon the land F 
Medical authorities of some sanitary experience are alone 
able to engage in such important pathological considera¬ 
tions, and it must strike every one who is interested in 
the subject, that a Boyal Commission, without any pre¬ 
tence of medical knowledge, is singularly incompetent 
to deal with such a matter. What importance the public 
or Parliament may attach to their recommendations I 
am unable to learn, except from former experience, but 
it is clearly our duty, as public health officers, to ex¬ 
amine the subject from a medical point of view, and I 
doubt not what will be the conclusion. 
Dr. Cobbold said that individually he regarded the 
sewage question as one which was three parts out of 
| four a chemical question. On this account he thought 
the chemists should have the advantage of speaking first 
upon it. Dr. Letheby had referred specially to the re¬ 
marks made by him in his brochure . Now, though the 
observations he made there were written in a warm, 
perhaps too warm a strain, he believed there was no 
statement which he was not still prepared to substan¬ 
tiate. And he thought since he had gained more ex¬ 
perience in experimental researches, that he could now 
write a pamphlet much more cogent than that to which 
Dr. Letheby had alluded. With reference to parasitic 
diseases, he would only say that he knew of two patients 
in this country who were suffering from that frightful 
malady which was so destructive in Egypt. These 
patients at every urinary discharge must pass a number 
of the eggs of this parasite, and if the number of persons 
so afflicted was increased fivefold, the chances of the ex¬ 
tension of this disease must likewise increase. But hap¬ 
pily there were so many contingencies which the para¬ 
sites had to encounter before they arrived at the human 
body that the community were yet spared; still he held 
by the statements contained in his pamphlet. Then 
take the case of ordinary tape-worm disorders, respecting 
which he had had much experience. There were about 
3000 persons in London suffering from this cause, who 
each passed from four to twelve joints a day, each joint 
containing 30,000 mature eggs, which would give at 
least a daily return of 450 millions, but he believed 1000 
million eggs was nearer the mark. A certain number 
of grains of organic matter per gallon were found by 
chemists in sewage, of which organic matter those eggs 
must be part and parcel. A handful of large entozoa 
parasites had been taken from the Craigintinny meadows. 
If this sewage was distributed far and wide, it was cer¬ 
tain that a considerable portion of these millions of eggs 
must gain access to the herbivora. It was known, from 
experimental researches, that measles were developed 
productively in beef. It was a popular notion that pork 
only developed measles, but he would assert that in 
underdone beef persons ran a greater risk. The pro¬ 
portion of tape-worm disease derived from measly beef 
was as seven or eight to one in the case of pork. It was, 
therefore, to incur an enormous risk to distribute sewage 
which contained these germs over the land. It was 
possible to decimate the population of any town within 
a certain number of months by the distribution of tape¬ 
worm germs, there being one tape-worm in particular 
which produced a disease of the human body at present 
causing the death of 400 persons annually in this country. 
If that parasitic disease should increase in the same pro¬ 
portion as other parasitic diseases, such as the ordinary 
tape-worm, a result would follow such as still obtained 
in Iceland, where one-sixth of the population died an¬ 
nually from this cause. Having these facts to deal with, 
and knowing the developmental process through which 
these parasites passed, he thought they were called upon 
to ask people to pause before adopting a scheme so 
gigantic as that now proposed, fraught as it was with 
consequences so serious as those which he believed were 
involved in it. 
Mr. Holland said he did not believe any portion of 
Dr. Letheby’s paper, and he thought the writer was in¬ 
consistent with himself. In the first place he alleged 
that twenty times its volume of water would purify the 
sewage poured into it, and afterwards he asserted that 
even a small quantity of water from irrigation meadows 
was poison. Was Dr. Letheby prepared to recommend 
that the soil should be burnt; if not, what did he pro¬ 
pose to do with it ? Unless he was prepared to recom¬ 
mend that all human manure should be burnt to avoid 
the supposed risk, his argument went for nothing. He 
(Mr. Holland) believed that the danger of spreading dis- 
