450 Report op Inspection Work of the 



There are given in addition, analyses of Arsenoid, Paragrene, 

 Blaok Death, Bug Death, and Hammond's Slug Shot. 



INTRODUCTION. 



During the year 1900, there were collected for analysis twenty- 

 two samples of materials sold as Pafis green, and also one sam- 

 ple each of Arsenoid, Paragrene, Black Death, Bug Death and 

 Hammond's Slug Shot. Of the twenty-two samples of Paris 

 green analyzed, ten represent firms whose goods were not exam 

 ined by us in 1899. 



CHEMICAL COMPOSITION OF PARIS GREEN. 



Paris green, or copper aceto-arsenite, may be regarded, when 

 chemically pure, as containing approximately 



Copper arsenate 82 per ct. 



Copper acetate 18 " 



However, it is customary, when speaking of the amount of 

 arsenic contained in Paris green, to refer to it as arsenious oxide, 

 and similarly the amount of copper is referred to as copper oxide. 

 Arsenious oxide, as such, and copper oxide, as such, are not pres- 

 ent in pure Paris green, and the use of these terms in giving the 

 results of chemical analysis is simply a convenient custom. Using 

 the usual form of expression, as thus explained, we should give 

 the composition of pure copper aceto- arsenite as follows: 



Arsenious oxide 58.64 per ct. 



Copper oxide 31.30 



Acetic acid 10.06 



When we say that this compound in pure form contains 58.64 

 per ct. of arsenious oxide, we mean that the amount of arsenic 

 present simply is equivalent to the quantity of arsenious oxide 

 stated, and not that arsenious oxide is present to that or any 

 other extent in the compound known as copper aceto-arsenite. 



Now, Paris green, as found in the market, rarely, if ever, con- 

 sists entirely of pure copper aceto-arsenite, but contains this 



