466 Intelligence and Miscellaiieous Articles. 



precipitate was recognized as arseniate of lead, — 1st, by the alliaceous 

 odour which it evolved when calcined on charcoal by the blowpipe ; 

 2ndly, by the brick-red colour which it immediately yielded by moist- 

 ening it with a neutral solution of nitrate of silver. From the 

 weight of this arseniate of lead, the quantity of arsenic contained in 

 the deposit from the waters of Wattviller, was deduced. This ex- 

 periment showed that 100 parts of the deposit, previously treated 

 with nitro-hydrochloric acid and afterwards dried, yielded 4'42 of 

 arsenic acid, containing 2*8 of metalHc arsenic. 



After having determined the proportion of arsenic, a direct expe- 

 riment was atttempted to determine the effect of this deposit on the 

 animal oeconomy. This experiment was made with a fresh quantity 

 of the same deposit, furnished by M. Chevallier. 



Forty grammes of this deposit, divided into two portions, were 

 forcibly given to a middle-sized young dog. Each dose of 20 

 grammes was diffused through a decilitre and a half of slightly viscid 

 honeyed water, and gradually introduced into the throat of the 

 animal. This liquid, which was swallowed without any apparent dis- 

 gust, occasioned neither vomiting nor uneasiness, for on offering 

 bread to the animal three quarters of an hour after swallowing, it 

 was readily eaten. The second dose was administered in the same 

 manner, and afterwards the animal eat about three ounces of brown 

 bread. No alteration of appearance could be detected by an atten- 

 tive examination of the animal, during six hours from the commence- 

 ment of the experiment, and no difficulty was observable in its diges- 

 tion, even in twenty-four hours. After this time the animal was re- 

 stored to bis usual diet, and there was no apparent alteration in his 

 health. 



The following conclusions may be fairly drawn from this first ex- 

 periment : — 



1st. In the natural deposits of the mineral waters of Wattviller, 

 arsenic exists to the amount of 2*8 per cent. 



2ndly. A portion of these deposits, representing 1-76 gr. of arsenic 

 acid, or 1-14 gr. of arsenic, produced no effect upon the health of a 

 dog. 



i3rdly. This non -action shows that the poisonous property of the 

 arsenic contained in these deposits, is destroyed by its combination 

 with peroxide of iron. 



4thly. This result confirms what experiment has already shown, 

 that peroxide of iron, by combining with arsenious and arsenic acid, 

 destroys their poisonous properties, and consequently becomes an an- 

 tidote for them, as proved long since by the direct experiments of 

 MM. Bunsen and Berthold Font. 



A second chemical experiment was made upon a certain quantity 

 of the deposits of the waters of Royat (Puy-de-P6me), sent to the 

 author by M. Chevallier; in this deposit, in which M. Chevallier and 

 M. Gobley had ascertairied the presence of arsenic, it was found to 

 amount to only ^^j^^dths, and in the state of arseniate. 



The last conclusion was deduced from the presence of arseniate of 

 iron and of lime, which was obtained from the deposit in hydro- 



