176 TEAR-BOOK OF PACTS. 



existence of arsenic in the iron pyrites found in coal may not be 

 considered perfectly novel, it certainly does not seem to be known 

 that arsenic is so widely disseminated as to form an ordinary con- 

 stituent of the coals burnt in our towns; and chemists of celebrity 

 have held, and now hold, it to be absent there. He had examined 

 fifteen specimens of coal in Lancashire, and found arsenic in thirteen. 

 He had also found it in a few others ; but Air. Binney having pro- 

 mised a collection, properly arranged, the examination will then be 

 made more complete. Mr. Dugald Campbell bad also lately found 

 arsenic in coal pyrites ; this had a very direct bearing on our sani- 

 tary knowledge, as we must now be obliged to add arsenic to the 

 number of impurities in the atmosphere of our large towns. It is true 

 that he bad not actually obtained it from the atmosphere ; but when 

 the pyrites is burnt the arsenic burns and is carried off along with the 

 .sulphur. One or two coal brasses (as they are called) contained 

 copper, a metal that is also to some extent volatilized, as may be 

 readily observed wherever copper-soldering takes place. Although 

 an extremely small amount of copper is carried up from furnaces, it 

 is not well entirely to ignore it. The amount of . however, is 



probably not without considerable influence ; and wo may piobably 

 learn the reason why some towns seem less affected than others by 

 the burning of coals, by examining the amount of arsenic burnt as 

 well as sulphur. — Philosophical Mmjazinc, No. 134. 



EFFECTS PRODUCED BY ARSENIOUS ACID. 



PROFESSOR SCHMIDT and Dr. fSttirzwage in Dorpat have made a 

 series of experiments on the action of Arsenious Acid, when intro- 

 duced into the circulation, on the oxidizing process in the body. The 

 mode of experimenting consisted in determining the normal quantity 

 of carbonic acid exhaled in an hour by certain animals (fowls, 

 pigeons, and cats), and then administering to them arsenious acid, 

 and again observing the quantity of gas exhaled in the same time. 

 The apparatus consisted of a bell-jar, standing on ,-i ground-glass 

 plate, under which the animal was placed. In the tubulure of the 

 irwere inserted two tubes, and a delicate thermometer. One 

 of these tubes communicated freely with the air, the other was con- 

 nected with a series of tubes for the absorption of carbonic acid and 

 water, and witli an aspirator by which a regulated quantity of air 

 could l)e drawn through the ByBtem. Each experiment lasted about 



an hour, during which time about SO to 85 Hires of :iir were drawn 



through : the carbonic acid of this air was determined by a m parate 

 experiment, ami allowed for. The secretion of urea was deteri 

 in some cases: the determinations were made by Liebig's method. 



From these experiments, Schmidt and SttLnwage conclude that 

 arsenious acid introduced into the organism occasions a considerable 

 diminution in the seoretian of matter. Tin- phenomena are most 

 observable in fowls ; but oven in oats, which vomit after tin' injection, 

 and are to be considered as starving, the diminution amounts to -■' I I r 

 cent., even after eliminating the diminution caused by mere inanition. 

 This fact explains the fattening of horses after the administration of 



