ANALYSIS <>K CNSEOTIOIDES AND FUNGICIDES. 89 



I (>MM i \ 1 . N \ \ \ I 



A glance at Table II at once makes it apparent that onlv 1 sample 

 out of more than 650 examined contains neither copper, acetic acid, 

 nor arsenious oxid this is sample No. 7. One other sample, No. !.'.!, 

 consists of about equal parts Paris (Ireen and some insoluble material 

 that appear* to be clay or infusorial earth. ( )ut of the total number 

 examined -".1 contained le-*s than .">o per cent ar-eiiiotis oxid. It will 

 be noted, however, that a number of these samples said to contain [ess 

 than :M per cent ar>enious oxid were analy/ed by a method (the 

 magnesium pyro-arsenate method) that has since been shown to jj'ive 

 results about 1 pel 1 cent low. I f a more accurate met hod of analvsis 

 had been used, the number falling below ;><> per cent arsenious oxid 

 would very likely be materially diminished. It aUo appear-* that the 

 Western States receive more of those samples that contain small per- 

 centages of arsenious oxid than do the Northern States. 



The State of Louisiana, which previous to IS'.W occasionally received 

 samples containing small percentages of arsenious oxid, does not 

 seem to have had any upon the market during 1S9D and llfuo. Out of 

 !>; Dimples of Paris (Jreen examined in New York State during the 

 years ls ( ,!> to 1901, inclusive, none was found that contained less than 

 50 per cent arsenious oxid. In both California and Oregon, until a 

 very recent date, quite a large amount of the Paris Green on the 

 market contained small percentages of arsenious oxid, although it is 

 said that this condition has been very much improved during the last 

 two years. 



Concerning soluble arsenious oxid in Paris greens, it appears that 

 those upon the market in California until recently contained very 

 large quantities, those in Idaho were very fair, only 2 out of li> con- 

 taining more than 4 per cent, those in Illinois. Montana, and Texas 

 contained very small percentages, and those in New York the same, 

 only 1 out of iK) containing more than 4 per cent. This one was 

 sample No. 204, containing l/UW per cent of free arsenious oxid. 



It must be borne in mind, however, in looking over the ligures for 

 free arsenious oxid that the results in one State can not be compared 

 with those in another, since the methods of analysis were very likely 

 different in every case and would lead to entirely different results. 

 It may be of interest to those who have not read the previous bulle- 

 tin of the Bureau of Chemistry on this subject to mention that out of 

 the 45 samples of Paris Green, from all parts of the I'nited State-. 

 which were examined 71 per cent contained more than 4 per cent 

 of soluble arsenious oxid and 16 per cent contained more than r, 

 per cent of arsenious oxid when a ten-day extraction of 1 gram with 

 LOUD cc of water was made. In view of the facts brought out in 

 that bulletin, a 6 per cent, rather than a 4 per cent, limit for soluble 

 arsenious oxid was advocated when the above method of nnaly.-i> 

 was employed. 



