New York Agricultural Experiment Station. 303 



the gas was allowed to act for several hours, the excess of water 

 being essential to prevent crystallization of by-product. 



The following tables show tests made in orchard fumigation 

 under box fumigators, hence should show approximately the 

 amounts of acid and water to be used to give most uniform 

 results within shortest period of time under varying field con- 

 ditions. 



The potassium cyanide used was what is known by dealers as 

 " broken cyanide 98 j)er ct. pure " and unless so stated no addi- 

 tional labor or cost was expended in order to have it of a definite 

 size. Except where indicated, chemically pure sulphuric acid 

 (98 per ct., sp. gr. by test 1.84) was used. 



Table IX. — Tests with Various Formulas for Fumigation. 



FORMULA 1-1-2. 



Reenlta. 



KCN In two pieces. By-product 



crystallized in 30 miu. Temp. 53.5. 

 7.0 7.0 14.0 35.0 10.0 KCN in two pieces. By-product 



crystallized, commercial sulphuric 



acid. 

 7.0 7.0 14.0 30.0 17.0 KCN in one piece. By-product 



crystallized, commercial sulphuric 



acid. 

 7.0 7.0 14.0 35.0 11.0 KCN in two pieces, one large, one 



small. Temp. 45°. 

 7.0 7.0 14.0 30.0 5.5 KCN powdered. Temp. 45°. 



formula 1-1-3. 



* Chcm. action not complete, com. acid. 



Chem. action not complete, com. acid. 



Chem. action not complete, com. acid. 



Chem. action not complete, com. acid. 



some large pieces of KCN. 

 Chem. action not complete, com. acid. 

 Chem. action not complete, com. acid. 



some large pieces of KCN. 



Chem. action complete, com. acid. 



Chem. action complete, com. acid. 



11.5 Chem. action complete, one piece KCN. 



Chem. action comijlete, com. acid. 



formula 1-1%-3%. 

 11.25 13.0 39.0 30.0 8.0 KCN in two pieces. Com. acid. 



* In oases where time of chemical action is not given, Ibe tests were made under tents where 

 the action could not be observed. 



