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Ternporntiire. ' F. Exlinustar Tar fog Inlet Outlet Inlet speed, grnins/100 cu. esliniistcr eslinuster LivEseys r.p.m. ft a 101 GI 3.2.;0 "3.5 104 ti; 3.12'8 27.7 111 ;9 3,000 110.0 2 97The increnserl nmount of tnr fog in the gns wns very efficiently reinovcd by the Livesey wnshers, probably becnuse of the incrensed size of the drops due to condcnsntioii of wnter niid tnr rapours. Tnr fq Outlet Licesey icnshersTcnipernttirc, F. l'nr fog hilet Oritlet Inlet Oiitlct gr./lOo CII. c*rhnuster edinustcr Lireseys 1,ivrwys Ile\-e.,'min. ft. 97 10; ;st 01 3,040 1 . ; S7 1031 o q U34 3.150 2.0It persisted in the pus though the aninionin wnsliers n s fnr ns the inlet to purifiers, aherc. the concentrntion wns nlso 1 to 2 prnins per 100 CII. ft.The sninll ninount of tar fog collected wns dry. FIG. 5 600 JJIJJI. rlio. junirhccl large c o d gas rrlitcusler 450,000 en. jl. hr., two slogc nrachine I t v;ns shown in n con1 gas strenin from continuous rerticnl retorts that \vet tnr fog could bc removed by nicniis of IL P nnd A Tar Estrnctor following n high-speed exhnuster and sccondnry condensers with nn efficiency of nbout 97%. Tnr fog Tcml~rnture, F. grnins/IOO cu. ft. Inlet Outlet Inlet Inlet Outlet Efficicnry esliniistcr eslinoster 1' & A l

By J. IDRIS JONES.Carbonyl chloride (1 mole) adds readily to an epoxide (1 mole) with formation of the corresponding 2-chloro-substituted chloroformate. With 2 moles of epoxide and 1 mole of carbonyl chloride the product is the corresponding bis-2-chloroalkyl carbonate. The direction of ring opening in some unsymmetrical epoxides has been established: opening appears to be unidirectional. Series of 2-chloro-substituted carbamates and N-substituted carbamates have been prepared from the chloroformates, and a convenient synthesis of N-substituted oxazolid-tones has been evolved based on the removal of hydrogen chloride from the mono-N-substituted chloroalkyl carbamates. The chlorine atom in 2-chloro-l-phenylethyl carbamate is readily hydrolysed and elimination of ammonia follows, to give phenylethylene carbonate (2-oxo-4-phenyl-1 : 3-dioxolan) . The reaction of thiocarbonyl chloride with epoxyethane has also been examined.1 : %EPOXIDES are highly reactive and many of their reactions have been studied in detail1 When this work was undertaken2 the reaction with carbonyl chloride had not been examined. With equimolar proportions it was found that ring opening occurs readily, with formation of 2-chloro-substituted chloroformates, but with 2 mol. of epoxide further

A study has been made of the behaviour on heating of the alkali-metal mono-and di-salicylates and *-hydroxybenzoates, and of some related substances. Some rate studies are reported for these reactions.When a mixture of 14C-labelled potassium carbonate and dipotassium salicylate was heated at 200" appreciable exchange accompanied the rearrangement with formation of labelled p-hydroxybenzoate. The mechanism of these reactions is discussed DIFFERENCES in behaviour of the alkali metals in organic reactions have often been noted.2739 4 The Kolbe-Schmitt reaction provides a classical examp1e.l' 2s 59 and Ost * drew attention to the remarkable difference in behaviour between sodium and potassium salicylate at 220". The former yielded disodium salicylate, the latter dipotassium $-hydroxybenzoate. There occur in the literature many conflicting reports concerning the thermal rearrangement of the alkali-metal salts of aromatic hydroxy-carboxylic acids. In large measure, these are due to the use of carbon dioxide as a supposedly inert atmosphere in the early studies of these rearrangement^,^^ lo for under these conditions it is possible for carboxylation to intervene.More recent studies have revealed differences not only in the ratio of orthoto parasubstitution, but also in the extent of carboxylation and in the tendency to form hydroxydicarboxylic acids, particularly at higher temperatures.6311 In the Marasse procedure also differences have been observed 11, I29l3 and these distinctions hold in the phenol, naphthol, and heterocyclic series.6In order to establish how far purely thermal rearrangements are involved in the Kolbe-Schmitt reaction, a study of the behaviour on heating of various alkali-metal derivatives of salicylic acid and other aromatic hydroxy-carboxylic acids was undertaken.Most of our experiments were conducted in vacuo; this served to minimise oxidation, and in those cases where carbon dioxide was evolved eliminated the possibility of recarboxylation. From our studies on the monoalkali-metal salts the following facts have emerged. Monosodium salicylate at 300" yields equimolecular amounts of phenol, carbon dioxide, and disodium salicylate. A mixture of sodium phenoxide and monosodium salicylate at 140" gives equimolecular amounts of free phenol and disodium salicylate.In 1875 Kolbe