Isomeric Naphthalene Derivatives.-Eighth Report of the Committee, consisting of Professor W. A. TILDEN and Professor H. E. ARMSTRONG. (Drawn up by Professor ARMSTRONG.)

The Conversion of Sulphochlorides into the corresponding Chloroderivatives. In the case of naphthalene derivatives no interaction is of greater practical importance than that which occurs when sulphochlorides are heated with phosphorus pentachloride, whereby they are converted into chloro-derivatives. At one time it was argued that reliance could not be placed on this interaction as a means of determining constitution, but of late years no such objection has been raised, and the idea that isomeric change may attend the displacement of the sulphonic radicle by chlorine appears to have been abandoned. The results obtained, especially by Cleve and by Dr. Wynne and the writer, are so uniformly consistent inter se that, bearing in mind the extent of the field covered, there is no longer room for doubt. Observations made during the past year are of interest as throwing light on the nature of the interaction.

There have long been instances on record of the conversion of sulphochlorides into corresponding chloro-derivatives and sulphur dioxide (RSO2CI=RCI+ SO2) by mere distillation. The successful use recently made of this method in the writer's laboratory in preparing chloro- and bromo-derivatives of camphor by Dr. Kipping and Mr. Pope has led him and Dr. Wynne to systematically study the behaviour of naphthalene sulphochlorides, which they had long known underwent decomposition, evolving sulphur dioxide, when heated. The conclusion arrived at is that, in all probability, phosphorus pentachloride acts merely by facilitating the resolution of the sulphochloride into sulphur dioxide and the chloro-derivative by attacking the former and converting it into thionyl chloride; and that, in fact, the chlorine in the chloro-derivative is not improbably the original chlorine of the sulphochloride and not chlorine derived from the pentachloride. In most cases the amount of chloro-derivative produced by directly distilling the sulphochloride is inferior to that obtained by means of pentachloride, as the decomposition is facilitated by the chloride, and therefore takes place at a lower temperature in its presence. There is always more or less of a resinoid condensation product formed on distilling the sulphochloride, but the amount is in some cases very small, while in others practically nothing else is obtained. On the other hand, in the case of compounds which are very readily chlorinated, the method permits of the production of chloro-derivatives corresponding to the sulphochlorides which are almost unprocurable from them by the ordinary method. For example, 1: 1'-chloronaphthalenesulphonic chloride yields a very large proportion of 1: 1'-dichloronaphthalene when distilled, although when heated with phosphorus pentachloride it is almost entirely converted into 141' trichloronaphthalene. The a-sulphochlorides appear all to decompose more readily and to yield a larger proportion of chloro-derivative than do the 6-sulphochlorides. It may be added that, taking into account the readiness with which change occurs during sulphonation, the non-occurrence of isomeric change on distilling sulphochlorides is probably significant.

Bromo-derivatives of Naphthalene. The conversion of naphthalene sulphobromides into corresponding bromonaphthalenes by means of phosphorus pentabromide is attended with great difficulty, as the bromide frequently acts almost exclusively as a brominating agent, owing to the readiness with which it is resolved into the terbromide and bromine. Far

better results are obtained in many cases by merely distilling the sulphobromide, although the formation of higher bromo-derivatives is not entirely avoided. During the year Mr. Jenks and the writer have made considerable progress in completing the series of bromonaphthalenes (di- and tri-derivatives), and in determining the nature of the sulphonic acids prepared from the dibromonaphthalenes by Mr. Rossiter and the writer.

One result of which mention may be made relates to the tribromonaphthalene obtained by Jolin by distilling nitro-1 4-dibromonaphthalene with phosphorus pentabromide, which hitherto has always been represented as the 1: 41' derivative, apparently because it is supposed that, as a rule, a-nitro-compounds are formed on nitrating naphthalene derivatives. Judging from the low melting-point of the tribromonaphthalene in question, it is improbable that it is a tri-a-derivative, as such a tribromonaphthalene should melt at a much higher temperature. The accuracy of this conclusion is established by the observation that 1 : 4dibromonaphthalene hetero-ß-sulphonic bromide is converted by distillation into a tribromonaphthalene which is undoubtedly identical with that prepared from nitro-1 4-dibromonaphthalene.

Attempts to devise a satisfactory method of preparing 1: 1'-dibromonaphthalene had been made by Mr. Jenks and the writer prior to Meldola's discovery of this modification, and as these have been continued to a successful issue reference may be made to the subject. The first method devised involved brominating the acetyl derivative of Guareschi's 14' bromonaphthylamine, prepared by brominating nitronaphthalene, &c.; this readily affords what appears to be a 1: 1'-dibromacetnaphthalide, but the greatest difficulty has been experienced in hydrolysing this compound.

A second method consists in nitrating 1 : 4-bromonaphthalene sulphochloride. A 1 : 1'-nitrobromosulphochloride is readily obtained, but, although the chief product, it is by no means the only one.

A third and far simpler method consists in heating 1: 4-bromonaphthalene sulphochloride with bromine and subsequently hydrolysing the 1:1-dibromosulphochloride, which is almost the exclusive product when the operation is properly carried out.

Although it is known that naphthalene-3-sulphonic acid is very readily converted into 1 : 4-dibromonaphthalene hetero-B-sulphonic acid, the order in which the bromine atoms enter has not been determined; and it is, in fact, difficult to arrest the action at an intermediate stage, the tendency to form the dibromo-derivative being very great. Mr. Stallard, however, having kindly placed a quantity of monobrominated 3-sulphonate at the writer's disposal, it has been ascertained that it is an a-bromo-33'-derivative. By heating naphthalene-6-sulphochloride with a molecular proportion of bromine a very satisfactory amount of 1 : 3'-bromosulphochloride is readily obtained. The 'repellent' influence of an acid radicle is clearly brought out by these results, as 3-bromonaphthalene yields 1: 2-dibromonaphthalene when brominated.

It is well known that there is often great difficulty, especially in the case of a-naphthol and a-naphthylamine, in obtaining satisfactory yields of bromo-derivatives, a considerable amount of by-product being formed, the nature of which has not been understood hitherto. Some light has been thrown on the nature of these products by observations made by Mr. Jenks and the writer.

Following the directions given by Cosiner and by Claus and Phillipson, monobrom B-acetnaphthalide was prepared by mixing bromine with B-acetnaphthalide dissolved in acetic acid; although the conditions were greatly varied, the amounts of pure product obtained were in all cases very unsatisfactory, rarely exceeding 25 per cent. The main product was a crystalline substance, more soluble in alcohol than monobromo-3-acetnaphthalide, but almost insoluble in acetic acid, ethylic acetate, chloroform, xylene and water. When digested with a weak solution of caustic soda this substance is converted into monobromo-3-acetnaphthalide, and the same effect is produced by digesting it with a solution of either sulphurous acid or potassium iodide. It appears to be probable that this substance contains the elements of a molecule of bromo-ẞ-acetnaphthalide and a molecule of bromine; such a compound would contain 56.6 per cent. of bromine. The highest amount found was 52 per cent. ; but as the substance undergoes decomposition when recrystallised from alcohol, it cannot be obtained pure. It is not produced by brominating bromo-3-acetnaphthalide, and therefore is probably formed together with it, being perhaps an addition compound, such as is represented by the formula

Br2

(NH.Ac) Br.

By digesting the crude product of the action of a single molecular proportion of bromine on one of 3-acetnaphthalide with a weak solution of caustic soda, and then recrystallising from spirit, as much as 75 per cent. of the theoretical yield of bromo-3-acetnaphthalide can be obtained.

Rule expressive of the Formation of Sulphonic Acids.-Dressel and Kothe, in a recent most interesting paper,' have taken exception to the 'rule' suggested by Dr. Wynne and the writer, referred to in previous reports, that there is an 'invincible objection' on the part of two sulphonic groups to remain in either contiguous, or para-, or peri-positions; they have described a tri- and a tetra-sulphonic acid, each containing two sulphonic radicles in contiguous ß ß positions. We shall have occasion to discuss their results when the investigation of the changes attending sulphonation-the most difficult and complex chapter of the subject-is somewhat further advanced. It is only necessary to say that the 'rule' was merely an expression of the results up to that time obtained, and was never intended as a final statement.

The Investigation of the Care at Elbolton.-Report of the Committee, consisting of Mr. R. H. TIDDEMAN (Chairman), Rev. EDWARD JONES (Secretary), Sir JOHN EVANS, Dr. J. G. GARSON, Mr. W. PENGELLY, and Mr. J. J. WILKINSON, appointed to ascertain whether the Remains of Paleolithic Man occur in the Lower Cave Earth. THE work of excavation in this cave has now ceased. Since our last report the débris from the cave mouth has been cleared away, and in some material that was taken from the upper Neolithic layer a flint flake was

1 Berichte, 1894, 27, 1193-1210.

found. Hitherto no flint tools had been discovered. A further depth of 10 feet was sunk to the bottom of the fissure, through a bed of sand and gravel, but no bones were found. The fissure still continues, being now only 5 to 6 feet in width. A total thickness of 60 feet has now been removed beneath the original cave floor. While an enormous quantity of bones have been obtained from the lower layer, yet no trace of Palæolithic man has been noticed, and, as this was the special purpose of the investigation, the Committee decided to bring the work to a close.

Fossil Phyllopoda of the Paleozoic Rocks.-Eleventh Report of the Committee, consisting of Professor T. WILTSHIRE (Chairman), Dr. H. WOODWARD, and Professor T. RUPERT JONES (Secretary). (Drawn up by Professor T. RUPERT JONES.)

1. Elymocaris Hindei, sp. nov.

CONTENTS.

2. Abdominal segments of a Phyllocarid from Moffat.

3. Discinocaris and Aptychopsis from Moffat.

4. Note on Macrocaris Gorbyi.

5. Small Estheria, undescribed, from the Coal-measures.

6. Estheria Dansoni from Nova Scotia.

1. A NEW species of Beecher's phyllocaridal genus Elymocaris, from the collection of Dr. G. J. Hinde, F.G.S., has been figured and described in the 'Geological Magazine' for July 1894, p. 292, pl. ix. fig. 7. It was found at Arkona, Ontario, Canada, in the Hamilton group of the Middle Devonian series.

Its nearest known ally is Elymocaris capsella (Hall and Clarke), from the Hamilton group of New York State, 'Palæont. New York,' vol. vii. 1888, p. 181, pl. xxxi. fig. 4. It differs, however, in details of outline, ornament, and ocular spot. The new species is named E. Hindei, after its discoverer.

2. Two imperfect sets of abdominal segments, impressed on a piece of Moffat Shale (from Garpel Linn), have been noticed in association with a carapace of Discinocaris Browniana, and therefore probably belonging to individuals of either that genus and species, or of Aptychopsis, or possibly Peltocaris, which also occur in the Moffat Shales. The two above-mentioned specimens are figured and described in the 'Geological Magazine' for July 1894, p. 291, pl. ix. figs. 4a, 4b. Fig. 3 shows the associated carapace. They belong to the Carlisle Museum.

We have noticed similar abdominal segments, but differing somewhat in size, associated with Hymenocaris in the Tremadoc slates, and with Ceratiocaris in the Upper Silurian beds. As such body-rings belong to various groups of these low-class Crustacea, it is not extraordinary that the above-mentioned genera should each possess the same kind of structure in the abdominal region.

3. A good-sized Discinocaris Browniana and the moiety of a rather large Aptychopsis Wilsoni, preserved in the Carlisle Museum, have also been described and figured in the July number of the 'Geological Magazine,' 1894, p. 292, pl. ix. figs. 5 and 6. They are typical of the Moffat Shales.

4. It may be remarked that the figured interior of the bipartite carapace of Macrocaris Gorbyi, Miller, referred to in our Tenth Report, at page 468, 'Report British Association' for 1893, appears (if looked at upside down) very much to resemble some of the bivalved Aptychopses figured in the Monograph of Paleozoic Phyllopoda,' Pal. Soc., 1892, pl. xv., but with a more acutely sagittate outline, and without the definitely concentric umbonal striæ.

If the carapace in the drawing (fig. 43) exposes its 'interior,' it seems to lie unconformably with respect to the body-rings, for they appear to be covered by the carapace upside down. If it normally covered the body, it would show its exterior.

Is it possible that after death, the attachments of the body and carapace having been loosened, the carapace turned quite over, and the parts of the animal floated into a position reverse to what they held in life? Or have we here two valves and an imperfect body of an Aptychopsis which during decay were washed into a reversed position-that is, with the abdomen projecting from the anterior region, as is not unusual with some fossil Ceratiocarida?

5. By favour of Dr. Wheelton Hind, F.G.S., we have very lately seer, from Mr. George Wild's collection, some pyritous specimens of what seem to be a very small Estheria in shale from the roof of the Bullion Coal, Lower Coal-measures, lately worked at Trawden, near Colne, in North-east Lancashire.

6. A specimen of Estheria Dawsoni, Jones (Geol. Mag.,' 1870, p. 220, pl. ix. fig. 15; ibid., 1876, p. 576; ibid., 1878, p. 101, pl. iii. fig. 2), has been obtained from the vicinity of Five-Islands, Nova Scotia, by Mr. H. Fletcher, of the Geological Survey of Canada. Like a former specimen, may be from the Horton Series; and has been sent by Sir W. Dawson, F.R.S., of Montreal, for our examination.

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Exploration of the Calf Hole Cave at the Heights, Skyrethorns, near Skipton.-Report of the Committee, consisting of Mr. R. H. TIDDEMAN (Chairman), Rev. E. JONES (Secretary), Professor W. BOYD DAWKINS, Professor L. C. MIALL, Mr. P. F. KENDALL, Mr. A. BIRTWHISTLE, and Mr. J. J. WILKINSON.

THIS cave lies on the west side of a limestone scar on the Heights Farm, and its entrance is about 30 feet above the plain at the foot of the scar. The entrance chamber is 33 feet long and from 14 feet to 26 feet in width. A well-buttressed column of rock supports the roof, forming two archway entrances to the cave. The outlook westward from these entrances is very fine, and the platform would be of value to prehistoric man as a shelter. At the north-east corner of the entrance chamber is another cave, here 8 feet wide, and which after a short course of 10 feet turns eastward. This latter cave was originally blocked up, and a former tenant of the farm attempted to open it out. He found a few worked flints, a long iron spear-head, and the bones of numerous small mammals. But the ignorance and want of skill of the workers made their finds of little value. August of 1893 your Secretary made some experimental trenches in the

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