ANAI.YSKS OF I NSKCTICI I ) KS A M > FUNGICIDES, 45 



None of tin- three anah -- i- Millieiently eomplete lo sho\\ -defini- 

 tively tlif chemical composition of the compound examined, although 

 from the data a> v;iven the Purple Poison appears to be at least par- 

 tially composed of London Purple or some do-dy allied product. 



[No. 2* I an. I \V.| 



The analysis of this .simple in the Bureau of Chemistry >ho\ved that 

 it contained ."i.s.-j-l per cent of total copper oxid. It is hasie in cha,'- 

 ueter and of somewhat variable eomposition. so that the purity can not 

 he calculated from the copper-oxid content. It contain--, however, a 

 >omewhat smaller amount of copper oxid than other samples examined 

 iu this lahoratorv. The method of analysis used \\a- that de>eribed 

 in Bulletin 68. 



FOSTITE. 

 < n/il/xixilioii of fo*titf. 



[No. 2SO.] 



Percent. 



Loss at dull-red heat .......................................... 2. 92 



Soluble in aqua regia: 



Copper oxid ........................ ..................... 2. 98 



Ferric oxid and alumina .................................. 1 . 36 



Calcium oxid ............................................ 2. 31 



Magnesium oxid ......................................... 1.51 



Sulphur trioxid ... ....................................... 3. 28 



Silica ..................................................... ::."> 



Insoluble in aqua regia ...... .................................. 83. 77 



Soluble in hot water .......................................... 7. 4'.' 



This material is said by the analyst to be composed of copper sul- 

 phate and finely powdered soapstone in the ratio of approximately 1:9. 



Sn.l'HATINK AND DKATH To K< )SK lU'tiS. 



TABLE X. <'<mii>oxitiim of Sulphqtine <m<l I>f<ith to lloxe Bugs. 



Neither of the above .substances has ever been examined in this 

 laboratory, but from the analyses it would appear that sulphur and 

 copper, probably as copper sulphate, are the active constituents. 

 These are diluted with inert materials, probably to mitigate their 

 action upon the foliage. 



