678 
RESEARCH FOR ARSENIC AND ANTIMONY. 
in order to stop the sulphur. The issuing gas, in each case, 
blackened paper wetted with the nitrate of silver. It had no 
effect on lead paper. A full red heat was applied to the tube 
just before the spot at which it was drawn out. A well- 
marked deposit of metallic arsenic was obtained in the cool 
and contracted part of the glass tube. This was estimated 
by comparative experiments at about l-250th part of a grain 
in a gallon of each water. The quantity was so small that 
no other test could be resorted to, excepting the process of 
Reinsch, which gave a clear arsenical deposit on a small piece 
of polished copper. The metallic deposit in the capillary 
tube had the appearance and entire volatility of arsenic. 
The amount of arsenic here found represented about one 
grain in two hundred and fifty gallons of water.* 
6. Sediment of a river .—Two ounces of a sandy sediment, 
collected from the bed of a small stream in Derbyshire—above 
any position from which arsenic could find its 'way into it from 
any artificial source—were mixed with hydrochloric acid and 
distilled. The acid distillate was perfectly clear and colourless. 
It yielded a well-marked quantity of metallic arsenic, when 
tested in the tube-apparatus, as also by Reinsctds process. In 
another sample, procured from the same spot, which had been 
distilled by Mr. Dugald Campbell, arsenic was also found, 
with traces apparently of antimony. 
7. Thames water .—Considering the above results as rather 
remarkable, and to a certain extent confirmatory of the 
opinion that arsenic is pretty widely distributed through soils 
* Samples of water taken at or about the same dates, from the same pipe, 
were examined by Dr. Miller and Dr. Lyon Playfair. The result was, that 
these gentlemen, acting independently, and employing entirely different 
methods of research, also found arsenic in this water. In their opinion, the 
arsenic proceeded from the refuse of certain chemical works on the stream ; 
but as the dried mud of the stream yielded only four tenths of a grain to a 
pound, and arsenic was found in the mud of the stream above all chemical 
works, it was, in the opinion of Mr. Campbell and myself, an impurity which 
might be explained by reference to natural causes. The Wiesbaden water 
contains a larger proportion of arsenic per gallon; and there are no chemical 
works to account for its presence there. 
In the e Chemical News ’ for August 25th, 1860, p. 127, Mr. Church has 
published the results of some experiments on the water of the river Whitbeck, 
in Cumberland. The water was alkaline, and when analysed yielded 
distinct indications of the presence of arsenic. The arsenic existed as 
arsenite—not as a mere trace, but in determinable quantity. In some 
seasons of the year the proportion approaches a good fraction of a grain of 
arsenic (metallic) in a gallon of water. The locality from which the stream 
-takes its origin is rich in minerals. Mr. Church found there arsenical 
cobalt, and from this the arsenic is probably derived. The arsenical w r ater 
is habitually used for every purpose by the inhabitants of the village of 
Whitbeck, and with beneficial rather than injurious results. This appears 
to show clearly that river water may be arsenical wholly independently of 
chemical works on the banks. 
