58 BACON. 



this product. Thus the principal reaction of benzaldehyde on dih_ydro- 

 limonene magnesium chloride would seem to be : 



CiJ-Ii-MgCl+CoH,CHO=C,H,COMgCl+C\„His- 



(Insoluble in (Soluble in 



ether.) ether.) 



The evidence for this assumption is made stronger by the following 

 experiments : 



Experiment 7. — The following quantities were taken: Limonene hydrochloride, 



3QO JJQO 2QO 



35 grams; specific gravity, —3- =0.9770 ; A-=-- =54.6° ; N-=—=1..47C8 ; magnesium 



powder, (5 grams; absolute etlier, 100 cubic centimeters. The reaction was carried 

 on throughout as in experiment 6, 23 gxams of benzaldehyde free from bfnzoic 

 acid being used. 



Soluble portion: This portion contained no magnesium. The total oil was 

 20.2 grams, from which, distilled in vacuo, the following fractions were olitained: 



No. 1: B. P. 75° to 78° at 25 millimeters, 17.2 grams. 



No. 2 : Residue 2.6 grams. 



The usual means of separation gave 4.5 grams of benzaldehyde phenylhydrazone 

 melting at 155° and 156°. The remaining oil, after the removal of the phenyl- 

 hydrazine, had the following properties: Boiling point, 174° to 176°; specific 



qno oAo oQo 



gravity, 2^=0.8248; N^ = 1.4590; Ai^=37°; it was therefore C,„H,s. 



S'Uinmary of the soluble portion. — Benzaldehyde 2.3 grams; C^^Tl^g, 

 14.7 grams; residue (diterpenes, etc.), 2.-5 grams. 



Insoluhle portion: The total oil was 31 grams, containing a trace of chlorine. 

 The product, distilled in vacuo, at 40 millimeters gave the following fractions: 



No. 1: B. P. 80° to 85° at 15 millimeters, 18 grams. 



No. 2: B. P. 85° to 215° at 15 millimeters, 7 grams. 



No. 3 : 3.5 grams of residue. 



There were obtained from the above, 22.8 grams of benzaldehyde phenylhydra- 

 zone melting at 156° and a liquid with the constants: Boiling point, 175° to 176°: 



qno ofio qno 



specific gravity, ^=0.8254; N^ = 1.4590; A ^ =36.8. There was also iso- 

 lated 1.1 gram of benzoic acid. 



Summary of the insoluble portion: — Benzaldehyde, 12.3 grams; 

 C'loHis, 7 grams; benzoic acid 1.1 gram, and 8.5 grams of inseparable, 

 high boiling compounds. The presence of the dihydro-limonene is proba- 

 bly due to imperfect washing of the insoluble solid by the ether. This 

 is readily understood when the sticky nature of this body is considered. 



Experiment S. — This experiment was not performed in the elaborate apparatus 

 we had constructed, but instead was carried out in a bromine flask in an atmos- 

 phere of dry hj'drogen on a water batli. 



The following quantities were taken: Ldmonene hydrochloride, 35 grams; mag- 

 nesium powder, grams. After the magnesium addition product had been formed, 

 23 grams of benzaldehyde were added. The usual violent reaction accompanied 

 by the separation of the yellowish solid took place, the whole being finally heated 

 with steam for fourteen hours, during which time the ether rapidly evaporated, 

 as an ordinary reflux Condenser does not hold that solvent in this climate. The 



