bon monoxide, and carbon dioxide with the nitrite ion peak at 355 µ is completely negligible. Similarly, chloride, bromide, hydroxide, nitrate, sulfate, and carbonate anions do not absorb above 300 µ.

The cross sections for quenching mercury resonance radiation by a number of mono- and di-olefins, acetylenes, substituted olefins, and other compounds containing multiply bonded atoms have been measured. The quenching cross sections of mono-olefins increase with increasing molecular weight but not with increased branching of the carbon skeleton. The position of the double bond has little or no effect on the cross section. The substitution of fluorine for hydrogen decreases the cross section of olefins. The presence of a second double bond does not alter the cross section. The double bond is more effective when between two carbon atoms than when it is between two nitrogens or carbon and oxygen. The cross sections of acetylenes are essentially the same as those of the corresponding olefins but here the substitution of N for CH does not appear to alter the effective cross section.

The presence of monothiocarbonate substituents in viscose has been demonstrated by the infrared spectra of the gases evolved during the acid hydrolysis of cellulose xanthate salts and viscose. A comparison of the results of various methods of sulphur determination and the results obtained by ultraviolet spectroscopy has been made. The results of investigations on sodium cellulose monothiocarbonate preparations support the concept of monothiocarbonate substitution. INTRODUCTIONSodiuin cellulose xanthate as normally prepared con~mercially from alltali cellulose and carbon disulphide is accompanied by nuinerous by-products. The composition of this mixture ancl of its solution in aqueous sodiuin hydroxide (viscose) changes as a result of complex hydrolytic and oxidative reactions. I t is well established that the proportion of trithiocarbonate, the main by-product, increases as a result of the hydrolysis of sodiuin cellulose xanthate and that hydrolysis and oxidation of the trithiocarbonate lead to sulphide, perthiocarbonate, and thiosulphate (1, 2, 3, 4). The presence of other components, often suggested to account for the complex reactions, is less clearly established. 1/Iono-and dithio-carbonate ions ( 5 , 6) have been invoked as intermediate stages in the xanthation and side reactions, and cellulose monothiocarbonate ions call be postulated as a reaction product of n~onothiocarbonate ions and cellulose ancl as a hydrolysis product of sodiuin cellulose xanthate. Monothiocarbonates yield carbonyl sulphide on acid hydrolysis and the presence of this substance among the gaseous products of acidified viscose would provide substantial evidence for the existence of such derivatives. RESULTS A N D DISCUSSION Infrared Spectra of Gases E'zolrded from AcidiJied ViscoseThe presence of carbonyl sulphide in gaseous mixtures containing carbon disulphide, carbon dioxide, and hydrogen sulphide can be demonstrated by the infrared spectrum, and considerably less than 5% call be readily detected by the most sensitive band a t 2030 cm-I (Fig. 1).The gaseous products of acidified viscose undoubtedly contained carbonyl sulphicle (Fig. 2, Table I), and essentially the same relative proportion of carboilyl sulphicle was obtained froin impure viscose and from a solution of sodium cellulose xanthate purified from small anions by passage through an anion exchange colunln (7). This observation strongly suggests that much of the carbonyl sulphide was chemically linlted to the cellulose, a conclusion supported by the observation that the viscose impurities formecl from alkali and carbon disulphide gave a much smaller proportion of carbonyl sulphide than freshly preparecl viscose. The relative proportion of carbonyl sulphide was smaller for a "ripened" viscose, an observation in agreement with the known fact that cellulose monothiocarbonate hyclrolyzes inore rapiclly than cellulose xanthate (8).These results are in agreement with those recently reported by Philipp (9), who I-llafanuscript

The production of metastable (3P0) mercury atoms in the quenching of mercury resonance radiation has been investigated with N2, H2, C2H4, C2H6, O2, and CO2. Metastable atoms, by virtue of their ability to induce the emission of electrons from a nickel surface, were detected with the first four gases; none was detected with O2 and CO2.