384 Scientific Intelligence. 



and O diminished until after some hours they became equal under 

 the same pressure. On continuing the spark the volumes in the 

 two tubes altered together, increasing or diminishing as the 

 nature of the spark varied. Since a white-hot coil of platinum 

 wire produces no permanent alteration of volume in dry C0 2 ; 

 and since Deville has shown the dissociation of C0 2 in contact 

 with white hot platinum ; it follows that the dissociated CO and 

 O must at once reunite under these conditions. Hence the author 

 predicted that a white hot platinum wire would produce complete 

 combination of dry CO and O, even without explosion. On heat- 

 ing the platinum coil to redness in the carefully dried mixture, it 

 at once glowed intensely and in a few minutes complete combina- 

 tion was found to have taken place. From this result the authors 

 conclude that while hydrogen unites with chlorine and iodine 

 directly, carbon monoxide and oxygen require an intermediary to 

 effect their combination. — J. Chem. Soc, xlvii, 571, August, 1885. 



G. E. B. 



5. On the direct synthesis of Benzene derivatives by the action 

 of Potassium on Carbon monoxide. — Nietzki and Benckiser 

 have repeated Lerch's experiments on the explosive compound of 

 potassium and carbon monoxide which is formed in preparing 

 this metal, and have proved that the derivatives he obtained from 

 it, trihydrocarboxylic, dihydrocarboxylic and carboxylic acids are 

 identical with the hexaoxybenzene, tetraoxyquinone and dioxydi- 

 quinoylbenzene respectively, already described by them. The 

 carbonyl-potassium was obtained by passing a current of CO, 

 completely dried and freed from oxygen, over potassium heated 

 to melting in a combustion tube. At the close of the experiment 

 the potassium had increased in weight about 70 per cent ; con- 

 firming Brodie's view that one molecule of CO was absorbed for 

 each atom of K. The product was a solid grayish mass with 

 here and there patches of a red-brown, green or black color. 

 After cooling, the tube may be filled with strong alcohol without 

 danger of explosion. On treating the crude product with hydro- 

 gen chloride, hexaoxybenzene C 6 (OH) 6 is produced, which proves 

 that the carbonyl-potassium is most probably C 6 (OK) 6 or potas- 

 sium-hexaoxybenzene. The former is accompanied however by 

 tetraoxyquinone, its first' oxidation product from which it may 

 perhaps be formed during the solution in HC1, by the reducing 

 action of the K still present upon the corresponding potassium 

 compouud directly produced : (CO) 6 + K 4 =C 6 (OK) 4 2 . To ascer- 

 tain this the freshly-prepared carbonyl-potassium was dissolved 

 in acetic oxide and precipitated by water. The brown precipi- 

 tate crystallized from glacial acetic acid gave the characteristic 

 hexaacetylhexaoxybenzene. The residue after treating the crude 

 product with alcohol is a dark green powder, which turns red in 

 the air, and which boiled with HC1 dissolves with a brownish 

 red color. On cooling the solution deposits stellate groups of 

 steel-blue needles of tetraoxyquinone C^OH) 4 2 . If the crude 

 product be washed with dilute alcohol it turns red and finally 



