Dirn^rox of chemistry 123 



SESSIONAL PAPER No. 16 



When it is remembered that it is seed of the same stock that is sown throughout 

 the series, the results will be of interest in showing the degree to which the quality 

 of the beet may lie modified by weather and cultural conditions. From the same 

 ^ced, beets were grown which yielded averages differing as much as 6-8 per cent sugar. 



It will be further apparent from these data that beets of excellent quality for 

 i-ugar extraction may be grown in many widely distant portions of the Dominion. 



INSECTICIDKS AND FUNGICIDES. 

 Arskxate of Lead. 



The reader is referred to the annual report of this Division for 1912 for a general 

 discussion of this insecticide, its composition, nature and use. It may, therefore, be 

 only necessary here to insert its more salient properties and enumerate the essential 

 features which will enable the orchardist to judge of the relative merits of the various 

 brands upon the market. 



This insecticide, it may be recorded, is steadily growing in popularity with fruit- 

 growers and for tlic spraying of shade and forest trees. In many districts, it has com- 

 pletely supplanted Paris green, the poison that was, until a few years ago, almost uni- 

 versally employed against ' biting ' insects. The reasons for this arc, chiefly, the 

 greater adhesiveness of the arsenate of lead to the foliage — thus lengtliening the period 

 of efficiency of the spray — that it is practically nou-iujurious to foliage, even in com- 

 paratively strong sprays and that the fine state of division in which this compound 

 exists prevents it from readily settling out of the spray, thus contributing towards a 

 xuiiform application of the poison on the foliage. 



The larger number of well known brands of the arsenate of lead paste — the form 

 in which it finds most favour with orchardists — contain in the neighbourhood of 50 

 per cent water, and less than .5 per cent of soluble arsenic oxide — the constituent that 

 burns the foliage. Some few years ago, this Division proposed, tentatively, a standard 

 a< follows: — 



' That any arsenate of lead paste to he aeconnted genuine shall contain at least 50 

 ■per cent arsenate of lead; that the arsenic oxide in such combination shall not he less 

 than. 12.5 per cent; that "the water soluble forms of arsenic should not exceed one per 

 cent calculated as arsenic oxide, and that there should he no admixture with foreign 

 materials to reduce or affect its strength.' 



Arsenate of lead is also sold as a dry powder, but its use in this form, either as 

 a ' dust ' spray or in the making of a liquid spray, has not found general favour. 



During the past year, thirteen samples have been analysefl and the data are pre- 

 sented in the following table. These brands, representing those found on the Can- 

 adian market and one or two specially imported for experimental purposes, were sub- 

 mitted by the Horticultural Division, which, during the past two seasons, has been 

 carrying on an extensive investigation in the Farm's orchard- and fruit plantations 

 with this insecticide. The samples for analysis were taken from the original con- 

 tainers. 



