314 FACTS AND OBSERVATIONS. 
‘ South London Analytical Laboratory, New Kennington Institute, 
289, Kennington Road, S.E. 
“Report on four samples of Thames mud, and two samples of grease, 
stated to be manufactured therefrom, received from the Editor of the South 
London Press : 
“ ‘ The mud was found to be capable of yielding fatty matter in the 
following small proportions : — 
No. 0. — Battersea 0'080 
No. 1. — Custom House .... 0T70 
No. 2. — Southwark Bridge . . . 0T36 
No. 3. — Dowgate Dock .... O’OGO 
“ c The grease was very dark in colour, offensive in odour, and, from the 
nature of the impurities it contained, it was evidently extracted from some 
waste material containing silica and earthy matters. About 80 per cent, 
of it was pure fatty matter, and it bore a resemblance in odour to some fat 
extracted from the mud, but was not ideniical in composition. 
“ ‘ On the whole, as I doubt very much if the trifling proportion of grease 
existing in the mud alone could ever be profitably extracted without adding 
some other source of fatty refuse, I can only fancy that your informant 
kept back part of the truth as to its origin, and I am quite certain that it 
is entirely unsuitable for the adulteration of butter, as it is so different 
from that substance. 
“ * John Muter, Ph.D., M.A., &c., 
“ ‘ Author of ‘ Popular Pood Analysis,’ &c. 
“ ‘ March 17, 1870.’ ” 
— South London Press. 
Studies on the Sewage-Water of Paris. — M. Che- 
valet. — From this paper we learn that the portion of the 
sewage soluble in water (the solid muddy deposit is converted 
into a kind of drv manure) contains by far the larger quantity 
of valuable ammoniacal salts, and retains in suspension 
nitrogenized organic matter, which it is never possible to 
obtain precipitated; there remains, moreover, similar organic 
matter in solution. The quantity of soluble ammoniacal 
salts amounts to 3‘37 1 kilos, to the cubic metre of sewage, 
and, in addition thereto, it contains 640 grms. of azotised 
organic matter. — Journal of the Society of Arts. 
An Inch of Rain, so often mentioned in meteorological 
reports, means a gallon of water spread over a surface two 
feet square; in other words, an inch of rain means a fall of 
100 tons of water upon an acre of land. — Ibid. 
Increase of Vipers. — A correspondent of the Journal des 
Connaissances Medicales writes to say that vipers have multi- 
plied enormously during the last few years, and that this is 
owing to the merciless destruction of the hedgehog, which is 
the natural enemy to all snakes, the venom of which pro- 
duces no effect upon it. 
