New York AGRICULTURAL EXPERIMENT STATION. 227 
“LonDoN PURPLE. 
SH GOMNUCS ga cas colt Sac Guile ma dvict chess bRcleiv ete cetet. 32.32 per ct. 
Rear -SOMIDles ACSENIOUS: OXIde. 2.25.0. 2. cs Sec ne ie ce wees a eas 12.27 per et 
PARAGRENE. 
Total arsenic equivalent to arsenious oxide....... 36501. 10%, 52°30 perc 
Water-soluble arsenious oxide................... 0.88 to 1.47 per ct. 
Copper equivalent to copper oxide............... 17.07 tO!) 2-06) permet: 
Calcium equivalent to calcium oxide (lime).................. 14.20 per ct. 
1S ELIRE cgi TERR RES eae fe goo 8.15 per ct. 
AOS EL GIDE CUS RaS AS ae er ieee gra ard ee ear 15.49 per ct. 
Midres-seluble arseniOus OXIde:. 0.2.6 ieee ce bie On ewes eed eceee 1.72 per ct. 
PO aN A aia ekg Se wie Sock oe ew nne ait emi one Pad Dee Oa. 16.02 per ct. 
SmitrH’s ELrectric VERMIN EXTERMINATOR. 
This is a mixture consisting chiefly of carbonate and hydrate of 
lime. 
ANALYSES OF COPPER COMPOUNDS USED IN SPRAY- 
iNGSPEANTS< 
An investigation was undertaken to ascertain whether the copper 
compounds used in making spraying mixtures are adulterated and 
whether the special preparations put on the market are pure, prop- 
erly mixed and economical in price. The following materials were 
examined: Copper sulphate in the form of crystals, powdered, and 
dried or anhydrous; copper carbonate as precipitated and “ hy- 
drated ;” a prepared mixture called “ copperdine ” in dry form and 
in solution; and a prepared bordeaux mixture. 
The samples of copper sulphate crystals contained 98.1 to 99.6 
per ct. of pure copper sulphate. Powdered copper sulphate con- 
tained 98.1 per ct. The dried copper sulphate contained about 80 
to go per ct. of what it should contain if entirely free from water 
of crystallization. 
The samples of copper carbonate contained ‘from 60 to go per 
ct. of pure copper carbonate. 
“ Copperdine ” is a mixture of ammonium carbonate and copper 
carbonate. It was found to be needlessly high-priced. 
A “Prepared bordeaux mixture ” was found to contain only 
three-fourths as much copper as it should. 
* Bulletin 41. 
