REPORT OF THE CHEMIST 193 



SESSIONAL PAPER No. 16 



of a small quantity of lime, the usual amount advised being 1 pound to each 1 pound 

 of Paris green, though this is probably much more than is absolutely necessary. 



Sal soda (more commonly known as washing soda) should chemically effect the 

 same purpose as the lime, though in the apparent absence of recorded experimental 

 data it would not be wise to generally advise the substitution. Arsenate of soda, as is 

 well known, is more or less injurious to foliage, but the compound formed in the mix- 

 ture under discussion would rather be arsenite of soda, regarding the action of which 

 on foliage I cannot find any reference. I, however, am of the opinion, drawn from a 

 general consideration of the whole subject, that lime would be better, or rather, safer 

 to use, since the soda-arsenic compounds are easily soluble in water, and hence more 

 likely to affect the foliage. 



To obtain the neutralizing effect of 1 pound of slaked lime, approximately 4 pounds 

 or ordinary crystallized washing soda would be required. This quantity of lime, how- 

 ever, as already pointed out much exceeds that absolutely necessary, and most probably 

 2 pounds washing soda (equivalent to \ pound of lime) would be ample. An experi- 

 ment recently made here showed that when 4 pounds of sal soda in solution were added 

 to a mixture of 1 pound of Paris green in 160 gallons of water, considerable traces of 

 arsenic went into solution ; in other words, that there had been a slight decomposition 

 of the Paris green. When, therefore, through inability to conveniently obtain lime, sal 

 soda is substituted, we should advise not more than 2 pounds to each pound of Paris 

 preen ; but in view of the general results of soluble arsenic compounds on foliage, and in 

 the absence of any definite data from spraying experiments with the mixture under dis- 

 cussion, it would be safer to use lime whenever possible. The arsenate of lime that 

 may be formed in the fluid from following this course has been shown to be non-inju- 

 rious to foliage and an excellent insecticide. 



It might be pointed out that when Paris green is used in Bordeaux mixture there 

 is no need for further addition of lime, to prevent injury to foliage, and that in this 

 mixture both the fungicidal and insecticidal properties are unimpaired. 



WELL WATERS EROM EARM HOMESTEADS. 



Eor the year November 30, 1900, to December 1, 1901, 96 samples of well waters 

 have been received for analysis. From the tabulated statistics in the letter of trans- 

 mittal it will be seen that while the largest number of samples were received from 

 Ontario, farmers in every province of the Dominion have availed themselves of the 

 privilege extended to them in this matter. 



Owing to insufficiency in the quantity sent, to dirty bottles or corks, &c, it was 

 found impossible or inadvisable to submit to analysis a number of the waters received, 

 and in this connection it may be well to again point out that the necessary instruc- 

 tions to be followed in collecting and shipping the sample will be forwarded to farmers 

 and dairymen upon application. 



We would further state that the examination of mineral or supposed medicinal 

 waters is not undertaken. 



Each water, as analysed, is reported upon to the sender and such advice given or 

 euggestions made regarding the water supply as the results would justify. These reports 

 cannot be inserted here, for want of space, but a brief statement regarding the quality 

 of the waters will be found in the last column of the appended table of data. 



Of the 64 waters submitted to complete analysis, 19 were reported as pure and 

 wholesome, 18 as decidedly suspicious and probably dangerous, 16 as seriously polluted, 

 and 11 as saline waters. 



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