SCIENTIFIC SUMMARY. 
89 
Association, which is reprinted by the “ Food Journal ” for December. The 
revelations then made as to the qualities of the shallow well-waters are 
such as to shock the feelings of any thoughtful man. The table is too long 
to quote in full, but a few facts from it will suffice. The total solid impuri- 
ties per gallon figure in enormous amounts, such as 256, 380, and even 507 
grains per gallon ; while the organic contamination runs through a rising 
scale till it reaches the almost incredible figure of 48J6 grains per gallon, 
in the very water holding 507-02 grains of solid matter in each gallon. 
Composition of the Water of the Nile. — The water of the Nile has recently 
undergone investigation by Herr 0. Popp (“Aimalen der Chemie,” September). 
The sample of water taken for analysis was obtained from the middle of the 
river, some six miles below Cairo. Previous to being analysed, the water 
was left standing for two days, after which time the water was first filtered ; 
but, even after this operation, it did not become quite clear, and it was found 
necessary, consequently, to leave it standing for some few days longer, when 
it deposited a flocculent sediment, which, on being tested, was found to 
consist of silica, a minute quantity of organic matter, lime, and magnesia 
salts. One litre of the water contains, in grammes weight — carbonic acid, 
0-03146; sulphuric acid, 0-003S0 ; silica, 0-02010 ; phosphoric acid, 0 00054; 
chlorine, 0 00337 ; peroxide of iron, 0 00316 ; lime, 0-02220 ; magnesia, 
0-01467; soda, 0 02110 ; potassa, 0-00468; organic matter, 0-01720; total, 
0-14238 grm. Percentage composition of dry residue — carbonic acid, 22-155 ; 
sulphuric acid, 2-755 ; silica, 14-150 ; phosphoric acid, 0-379 ; chlorine, 
2-372; peroxide of iron, 2-227 ; lime, 15-640 ; magnesia, 10-332 ; soda, 14 852; 
potassa, 3-300 ; organic matter and small quantity of ammoniacal salts, 
12-025 ; total, 100-187. 
Detection of Sulphur in Coal-Gas. — In a recent number of the “ Journal 
fur Gasbeleuchtung,” Herr Ulex gives the following method. Let a platinum 
basin be filled with half a litre of water, and the basin be heated over a 
Bunsen-burner until all the liquid has evaporated ; the basin will be found 
to be coated, on the outside, where it has been struck by the flame, with a 
dirty, greasy looking substance, which, on being washed off with pure dis- 
tilled water, and tested, proves to be sulphuric acid. The author further 
points out that the glass chimneys used with Argand gas-burners soon 
become coated over internally with a white substance, which, on being 
washed off with distilled water, will be found to be, on testing, sulphate of 
ammonia. The glass panes of a room wherein gas is burned for a few even- 
ings consecutively will, when rubbed with the fingers of a clean hand, im- 
part to it a substance which, on the hand being rinsed in distilled water, 
will yield a precipitate of sulphate of baryta with chloride of barium, and a 
brick-red precipitate with potassio-iodide of mercury. 
Powdering Camphor. — In the “American Journal of Pharmacy ” for No- 
vember, Mr. W. Proctor gives some hints as to the above. It is well known 
that camphor is easily reduced to powder by rubbing with a few drops of 
alcohol, but the powder so made will, after a short time, aggregate to 
crystals, which have to be rubbed down again. The author mixes with the 
powder of camphor so obtained, carbonate of magnesia, 10 grains to the 
ounce being sufficient; this powder never cakes or forms crystals. 
A Sensitive Test for Hyposulphites is given by Dr. Boettger in the u Journal 
