570 SANITARY NOTES ON TOT ABLE WATER, 
instant* excepting the portion which may have remained within 
its pores. Again* we must recollect he did not employ “ water” 
for his experiments* but urine* and thus had* to use his own 
figures* a minimum of 15*000 and a maximum of 45*000 
parts of nitrogen for every part of nitrogen in Thames water* 
excluding from the latter the nitrogen as nitrates and nitrites. 
Had I ever committed the absurdity of proposing that we 
should render ourselves independent of our water-supplies by 
allowing the water to circulate alternatively through our 
body and the filter* Lewin's experiments might have stood; 
but as it is everyone must form his own opinion of the merits 
of his report. 
I will here contrast Lewin's report with another which 
reached me only yesterday. It is by the Royal Prussian 
Military Administration at Coblenz* dated May 11* 1879. 
Towards the latter part of 1877 an outbreak of an epidemic 
of typhoid occurred in the Empress's own regiment* stationed 
in one of the fortresses at Coblenz. It was stated to me* the 
wife of a corporal had been visiting* and was laid up shortly 
after her return with enteric fever. Subsequently the disease 
spread so alarmingly that it was atone time contemplated to 
evacuate those barracks, as it was considered impossible to 
prevent excremental pollution of the water-supply. No doubt 
could therefore exist that* typhoid having once gained a 
footing* also specifically infected matter occasionally mixed 
with the water. 
At this stage one of the medical officers suggested to the 
Empress that the spongy iron filter might perhaps be the 
means of improving the sanitary condition of the garrison. 
She at once ordered one* which was started in December* 
1877* and another was ordered later on. 
After referring* in the first instance* to the great difficulty 
of tracing a direct connection between purification of the 
water-supply and the disappearance of an epidemic* the report 
contains the following passage* which I have verbally trans¬ 
lated : 
“ Nevertheless* I cannot but attribute the prevention and 
non-recurrence of new cases of typhoid in a great measure to 
the improved state of the drinking water by the spongy 
iron filter* the more so as a large number of chemical 
analyses has proved undoubtedly that the organic matter* 
nitric acid, and hardness* were considerably reduced after the 
filtration." 
After an outbreak of typhoid in Fort George* in Scotland, 
in the early part of last year, a very large spongy iron filter 
was ordered. Later on the filtering area was doubled. Acci- 
