64 BACOK. 



their derivatives, and thus a very simple and accessible means of iJrejjar- 

 ing tetra- and hexahydro-ljenzene derivatives is at hand. 



It has heen pro\'ed by quantitative experiments that with hydro- 

 linionene magnesium chloride, benzaldehyde acts as if it contained a h}"- 

 droxyl group. 



The solid product of the action of benzaldehvdc upon hydro-limoneue 

 magnesium cliloride gives analytical data whicli j^oint to tlie formula 

 CgHjCOMgCl. Wren decomposed with dilute acids this compound re- 

 geirerates nearly quantitative amounts of benzaldehyde, and only when 

 it had Ijeen heated for a long time are products like benzoin obtained, 

 wlrich would indicate a double molecule. 



The eomjjound C„H-COMgC'l is, when freshh' prepared, very unstable 

 in the air, its behavior being much like that of sodium acetone. Acetone, 

 like benzaldehyde, also reacts as if it contained a hydroxyl group. 



No analogous reaction was obtained from benzyl nragnesium chloride 

 and benzaldehyde. 



Work with the Grignard reaction in the field of the terjjenes will be 

 continued. 



