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PRELIMINARY INVESTIGATION OF THE
FLUORESCENT AND ABSORPTIVE SPECTRA
OF THE URANIUM SALTS.*

By HENRY MORTON, Ph.D.,
and H. CARRINGTON BOLTON Ph.D,
(Continued from p. 246).

NEWS.

The various di-uranic and double phosphates already named yield the same fluorescent spectrum, with no difference but a variation in brightness, and this spectrum is shown at 3 of Fig. 15. It so happened that the first specimen examined was one of di-uranic phosphate pre

Uranic Phosphates.

THE salts of this class which we have examined are the pared in the usual way, which gave a double spectrum, as shown at 8 of Fig. 1. Of this, the upper and fainter series following:of bands corresponds with the above general di-uranic spectrum, while the other, which disappears on drying, no doubt belongs to some hydrate which we have as yet been

unable to identify.

Mono-uranic phosphate,
Di-uranic phosphate,

U2O3.2HOPO5+3HO
2(U2O3).HO.PO5+3HO
Di-uranic phosphate hexahydrate, 2(U20)HOPO+6HO
Di-uranic phosphate octohydrate, 2(U2O3)HOPO5+8HO
Uranic pyrophosphate,
2(U2O3)PO5
Calcio-uranic phosphate, CaO.2(U203) PO5+SHO
Cupro-uranic phosphate, CuO.2(U2O3) PO5+8HO
The phosphates, like the arseniates, show a remarkable
fixity of spectrum, so that, with the exception of the first,
all these compounds show the same spectrum of fluo-
rescence. With regard to their absorptive action, a little
more variation is manifested.

Mono-Uranic Phosphate, U203.2HO.PO5+3HO.-This salt was formed by dissolving uranic hydrate in glacial phosphoric acid. The solution was evaporated in a desiccator until it attained a gelatinous consistency; in this

FIG. 15.

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opaque, of a rich green colour, and very billiant fluorescence. Its spectrum, shown at 1 of Fig. 15, consisted of very broad bands, leaving only narrow dark spaces between them. The material in its gelatinous state, and also the dilute solution, fluoresced, and gave a spectrum in which all the bands were displaced downwards in the spectrum, and are more rounded in character; this spectrum is shown at 2 of Fig. 15. The absorption spectra in these two cases are also well marked, and are given in Fig. 16-1 being that of the solid salt, and 2 of the solution. Both salt and solution held an excess of phosphoric acid.

The absorption spectra of these salts present a considerable variety of forms. That of the mixed hydrates just mentioned is shown in 8 of Fig. 1, that of the calcio salt at 9 of the same figure, and that of the di-uranic phosphate at 3 of Fig. 16. We have obtained others, but have not yet determined the hydration of the specimens yielding them. It seems likely that these may afford a means of distinguishing some of these salts where their fluorescent spectra are identical.

Sulphates.

The general rule, that bases of the formula U2O3 require 3 equivalents of a monobasic acid to form neutral salts, is conspicuously violated by the element uranium, and it was this peculiarity in the constitution of uranium salts which prompted Peligot's assumption of the so-called uranyl theory: thus, neutral uranic sulphate has the composition U203SO3+3HO, or, according to Péligot, (U2O2)OSO3+3HO. This salt is easily obtained by acting on uranic nitrate with concentrated sulphuric acid, or by treating uranic oxide with strong sulphuric acid, and in either case expelling the excess of acid by raising the temperature to about 300° C. The mass is then dissolved in water, and the solution evaporated to the consistency of a syrup; after standing for some time, small lemon-yellow crystals form, which may easily be separated from the mother-liquid. As thus obtained, the salt, according to the best authorities, contains 3 equivalents of water, 2 molecules of which are driven off in a current of dry air at 100° C., but the third molecule is given up only on heating to about 300° C. In this anhydrous state, the great affinity of the sulphate for water is noticeable; each drop as it strikes the mass hisses, and is converted into steam. On dissolving the neutral salt in strong sulphuric acid, and crystallising by spontaneous evaporation, an acid salt, U203SO3+HOSO3, is obtained. This uranic disulphate forms small needles grouped in warty concretions, and is of a much greener hue than the neutral sulphate. As will appear below, the spectrum of

[graphic]
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Phosphates.

state it remained for weeks without crystallising. A | the salt is quite different from that of the neutral portion was then transferred to a small specimen-bottle one. for examination, when it soon began to crystallise in an almost solid mass. Crystallisation also began in the larger quantity, where it had been disturbed, and soon (in a few days) pervaded it also. The material thus formed was *Communicated by President Morton.

A trisulphate is described by Berzelius, but its existence is denied by Péligot. Its formula, according to the uranyl theory, would be (U2O2)O3SO3, which is highly improbable. At present writing, attempts to obtain a trisulphate with a definite spectrum have been unsuccessful

Ordway (Am. Fourn. Sci., [2], xxvi., 208, 1858) obtained a tribasic sulphate, 3U2O3.SO3, by treating a solution of the normal salt with baric carbonate; this compound, as well as the minerals johannite, zipperite, uranochalcite, medjidite, voghanite, and uraconite (Dana)-different varieties of hydrous uranic sulphate,-have not as yet been examined.

The optical study of the uranic sulphate was attended at the outset by great difficulties, arising from the fact that, after several specimens had been studied which gave the same spectrum-that, namely, shown at 1 of Fig. 17,others, prepared under what were supposed to be identical conditions, showed such spectra as from previous experience we had reason to believe indicated the existence of a ture (see 3, Fig. 17). After seeking in vain for any impurity, it became at last evident that these mixed spectra resulted from the presence of the salt in two states of hydration, which depended upon very slight variations in their mode of crystallisation and subsequent exposure. It

FIG. 17.

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We have as yet been unable to isolate the substance giving these bands, but we have no doubt that they belong to the bihydrate of the uranic sulphate. By continuing to heat the substance in which this double spectrum has been developed we can reduce the strength of the bands belonging to this unisolated substance, and relatively strengthen those of the other, a small amount of water being at the same time expelled; but we cannot apparently reduce the mixture to the condition of the mono-hydrate alone. Thus a sample which had lost 5.7 by being heated suddenly to 100°, and refused to lose more at that temmix-perature, by heating to 150° C. lost o'5 per cent more, and then maintained a constant weight. The spectrum in both cases being of the same duplex character, and differing only in the relative strength of the two sets of bands.

If this same salt in a normal state is placed suddenly in an oven at 150° it will lose about 8.7 per cent of water, but will again still show the same double spectrum, but with a loss of brilliancy in fluorescence. It therefore seems highly probable that in this case the salt has in part been reduced to an anhydrous condition in which it has no fluorescence.

Uranic Sulphates.

required, however, a long course of experiments to develop these facts, and to fix even some of these conditions, and others yet await further investigations.

To put the matter in its most concise shape, we will here briefly state the results so far obtained. When the uranic sulphate crystallises from a cold solution by evaporation in the air, or sometimes by cooling from a hot solution, it takes up 3 atoms of water, and yields the spectrum shown at 1, Fig. 17, which may be regarded as its normal spectrum. The presence of a moderate excess of acid does not seem to effect this, though it has a decided influence on the subsequent behaviour of the salt.

If this salt is exposed to the air until adherent moisture has been carried off, and is then slowly dried, at first below and then at 100° C., it will lose 2 atoms of water and pass to the condition of the mono-hydrated salt. It then yields such a spectrum as is shown at 2 of Fig 17. If, however, the drying is carried on rapidly, as, for example, by placing the moist salt in a hot-water oven already at 100° C., evaporating the solution nearly to dryness on the water-bath, or occasionally even by drying over sulphuric acid, an amount of water is lost varying between 49 per cent and 57 per cent, and a double spectrum is developed, in which one set of bands seems to correspond with those of the mono-hydrate, and the

other set to be unlike those of the normal salt (see 3 of Fig 17).

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The formation of certain of these hydrates seems to depend upon the combined action of heat and moisture due to the suddenness of the heat, which in driving out the water from part of the salt bathes another part in its hot vapour. We have made some experiments in the direction which this suggests, but as yet without reaching a decided result. There are, however, some analogous cases to which we would call attention. Thus the blue hydrate of cupric oxide changes to black anhydrate by a heat of 100° when diffused in water; so the ferric hydrate. Again, a solution of CIO.SO3+3HO yields, on heating, crystalline flakes of 2(CIÓSO3+3HO, or abandons half its water. From what has been done, however, we think that we may, without risk of error, assume that the neutral uranic sulphate forms three hydrates with one, two, and three equivalents of water respectively, and that each of these has a distinct and characteristic spectrum.

The uranic disulphate gives a spectrum in which the bands are much less defined than are those of the normal salt, and are also less unlike in the abruptness with which they shade off on their upper and lower edges. The positions of their centres or brightest parts are given in the following table :

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Spectrum of Uranic Disulphate.

Bands. 1.

2.

3.

4.

5.

6.

7.

8.

33°2 408 48°4 57.6 66.8 764 860 94'0 65:8 If this salt is dried over sulphuric acid it has its fluorescence somewhat reduced, and the position of its bands is elevated in the spectrum, as the following table will show:Spectrum of Dried Uranic Disulphate.

2.

3.

4.

5.

6.

7.

8.

Bands. 1.
33 2 412 49°2 58.5 68.0 78.0 87.6 96.8
In solution the above-mentioned salts fluoresce with
moderate brightness, and give banded spectra, the position
of whose lines does not seem to differ from that of the
solid salt. If a solution is made in strong sulphuric acid
the fluorescence is very bright, but the position of the
bands seems to be unchanged. In these solutions, how-
ever, the bands are in all cases less defined than in the solids.

The absorption-bands of the neutral and acid sulphates are shown in 1 and 2 of Fig. 18 respectively, and in 3 we find the bands of the solution of either of these, or, indeed, of any other uranic sulphate which we have yet camined.

NEWS

It would seem with the sulphates, as with the acetates,, supply of fine iron filings, this quantity could not be that all are reduced to the same condition when in solution, obtained. Let anyone who doubts this borrow a blackand that this condition seems to be that of the neutral smith's vice, a fine file, and a piece of soft-iron, then take acetate. There is, however, this decided want of off his coat and try how much labour will be required to parallelism in the two cases, that, whereas an excess of produce a single ounce of filings, and also bear in mind acetic acid is necessary to bring out the spectrum of the that fine files are but very little used in the manufacture acetates, an excess of sulphuric acid seems to have no of iron. As the price of a commodity rises when the effect. The fluorescence, also, of these solutions is un- demand exceeds the supply, the Chinaman would have to affected by an excess of acid, or, rather, is very much pay far more for his adulterant than for the leaves to be brighter where pure sulphuric acid is the solvent than in adulterated. As Chinese tea-growers are not public the aqueous solution. analysts, we have no right to suppose that they would (To be continued). perpetrate any such foolishness.

The investigations recently made by Mr. Alfred Bird, of Birmingham, show that the iron found in tea leaves is not in the metallic state, but in the condition of oxide, and he confirms the conclusions of Zöller, quoted by Mr. J. A. Wanklyn in the CHEMICAL NEWS, of October 10, viz., that compounds of iron naturally exist in genuine tea.

It appears, however, that the ash of many samples of black tea contains more iron than naturally belongs to the plant, and accepting Mr. Bird's statement that this exists in the leaf as oxide mixed with small siliceous and micaceous particles, I think we may find a reasonable explanation of its presence without adopting the puerile theory of the adulteration maniac, who in his endeavour to prove that everybody who buys or sells anything is a swindler has at once assumed the impossible addition of iron filings as a make-weight.

In the first place we must remember that the commodity in demand is black tea, and that ordinary leaves dried in an ordinary manner are not black but brown. Tea leaves, however, contain a large quantity of tannin, a portion of which is, when heated in the leaves, readily convertible into gallo-tannic or tannic acid. Thus a sample of tea rich in iron would, when heated in the drying process, become by the combination of this tannic acid with the iron it contains, much darker than ordinary leaves or than other teas grown upon less ferruginous soils, and containing less iron.

"IRON FILINGS" IN TEA. By W. MATTIEU WILLIAMS, F.C.S.

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I HAVE watched the progress of the tea controversy and the other public performances of the public analysts with considerable interest; it might have been with amusement, but for the melancholy degradation of chemical science which they involve. Among the absurdities and exaggerations which for some years past have been so industrially trumpeted forth by the pseudo-chemists who trade upon the adulteration panic and consequent demand for chemical certificates of purity, the continually repeated statements concerning the use of iron filings as a fraudulent adulterant of tea takes a prominent place.

I need scarcely remark that, in order to form such an adulterant, the quantity added must be sufficiently great to render its addition commercially profitable to an extent commensurate with the trouble involved. Now the gentlemen who, since the passing of the Adulteration Act, have by some kind of inspiration suddenly become fullblown chemists, have certified to wilful adulteration of tea with iron filings, and have obtained convictions on such certificates, when, according to their own statement, the quantity contained has not exceeded five per cent in the cheapest qualities of tea. Now the price of such tea to the Chinaman tea-grower, who is supposed to add these iron filings, is about fourpence to sixpence per pound; and we are asked to believe that he will fradulently deteriorate the market value of his commodity for the sake of this additional 1-20th of weight. Supposing that he could obtain his iron filings at twopence per pound, his total gain would thus be about 1-10th of a penny per lb.

But can he obtain such iron filings in the quantity required at such a price? A little reflection or a few figures will render it evident that he cannot, and that such adulteration is utterly impossible.

I find, by reference to the Grocer of November 8th, that the total deliveries of tea in the Port of London during the first ten months of 1872 was 142,429,337 lbs., and during the corresponding period of 1873 139,092,409 lbs. Of this, about 8 millions of pounds in 1873, and 10 millions of pounds in 1872, were green, the rest black. This gives, in round numbers, about 160 millions of pounds of black tea per annum, of which above 140 millions come from China. As the Russians are greater tea drinkers than ourselves-the Americans and British colonists are at least equally addicted to the beverage, and other nations consume some quantity-the total exports from China may be safely estimated to reach 400 or 500 millions of pounds. Let us take the smaller figure, and, adopting the more moderate statements of the adulteration panic mongers, suppose that only one-fourth of this is adulterated, to the extent of 5 per cent, with iron filings. How much will be required? Just 5 millions of pounds per annum. Now it must be remembered the coarse filings could not possibly be used; they would show themselves at once to the naked eye as rusty lumps, and would shake down to the bottom of the chest; neither could borings, nor turnings, nor plane-shavings be used. Nothing but fine filings will answer the supposed purpose. I venture to assert that if the China tea-growers were to put the whole world under contribution for their supposed

This being the case, and a commercial demand for black tea having become established, the tea grower would naturally seek to improve the colour of his tea, especially of those samples naturally poor in iron, and a ready mode of doing this is offered by stirring in among the leaves while drying a small additional dose of oxide of iron, if he can find an oxide in such a form that it will spread over the surface of the leaf as a thin film. Now it happens that the Chinaman has lying under his feet an abundance of material admirably adapted for this purpose, viz., red hæmatite, some varieties of which are as soft and unctuous as graphite, and will spread over his tea leaves exactly in the manner required. The micaceous and siliceous particles found by Mr. Bird are just what should be found in addition to oxide of iron, if such hæmatite were used.

The film of oxide thus easily applied and subjected to the action of the exuding and decomposing extractive matter of the heated leaves would form the desired black dye or "facing."

The knotty question of whether this is or is not an adulteration is one that I leave to lawyers to decide, or for those debating societies that discuss such interesting questions as whether an umbrella is an article of dress. If it is an adulteration, and as already admitted, is not at all injurious to health, then all other operations of dyeing are also adulterations, for the other dyers, like the Chinaman, add certain impurities to the silk, wool, or cotton, in order to alter their natural appearance, and give them the false facing which their customers demand, but with this difference, if I am right in the above explanation, that in darkening tea nothing more is done but to increase the proportion of one of its natural ingredients, and to intensify its natural colour, while in the dyeing of silk, cotton, or wool, ingredients are added which are quite foreign and unnatural, and the natural colour of the substance is altogether falsified.

ON THE

ACTION OF BROMINE ON THE WATER-SALTS OF SUCCINIC, MALIC, MALEIC, AND PYRO-CITRIC ACIDS,

CRITICALLY EXAMINED AND INTERPRETED FROM THE
STANDPOINT OF THE "TYPO-NUCLEUS THEORY.

By OTTO RICHTER, Ph.D.
(Concluded from p. 248).

PART II.

On the Principal Molecular Changes that attend the Action of Bromine on the Water-Salts of Pyro-Citric Acid. WHEN the three isomeric modifications of pyro-citrate of water aretreated with bromine, the resulting dibrominated meta water-salts are expressed by the collective formula7) 2HC6Br; H2O2. H2O2. a) 2(HC2Br: C2: C2); H2Bг2: 2H ; 2C2O3 ~ 2H ; 2C2O3. B) 2(HC4Br: C2);

In this process the bromine is understood to act in accordance with the second method, so that the first stage will be marked by the direct union of 2 mols. of bromine with the complex carbon adjunct.

In the next stage 2 mols. of water suffer decomposition, their oxygen serving to oxidise the formous acid principal, while their hydrogen, by reacting upon the dibrominated carbon adjunct, gives rise to a molecule of hydrobromic acid, which, by transposing with the colligated alcohol, completes the formation of the new compound.

The reader, by taking his cue from the behaviour of the ortho-succinate under similar circumstances, will not be slow to perceive that the dibrominated derivative of the ortho-pyro-tartrate, which is the next upper homologue of the succinate, ought to be expressed by the formulaH2O2. H2O2.

a) 2(H2C2: C2) ; H2Bг2 ~ 2C2 ; H2Bг2 : 2C2O3 ~ 2C2O3 ; B) 2H2C4;

but although Lagermann and others have tried to obtain this compound by the usual method, they do not seem to have arrived at satisfactory results.

In connection with this subject a singular fact has been brought to light, which is, that under the influence of sodium amalgam these three varieties of meta-dibromopyro-tartrate agree with their parent molecules, the three varieties of pyro-citrate, in producing but a single variety of ortho-pyro-tartrate, instead of the three which are indicated by theory. In order to account for this discrepancy, I proceed upon the hypothesis that the three varieties of meta-pyro-tartrate are actually formed at the commencement, but that in the existing conditions they are speedily made to merge into the ẞ variety of the orthopyro-tartrate.

experience under the influence of certain chemical reagents. When the salts of these three varieties are boiled with water, carbonic acid is given off, and two varieties of dibromo-butyrate are left behind. Their formulaH202.

a) 2(H2C2: C2); H2Br2 ~ 2C2 ; H2Br2 : 2H ; 2C2O3,
B) 2H2C4;

is based upon the following train of reasoning:

In the first stage, 2 mols. of water yield up their oxygen to the formic acid ally; while their hydrogen, by reacting upon the bromo-hydrocarbon adjunct, gives rise to a molecule of hydrobromic acid, whose immediate union with a molecule of formen, &c., completes the formation of the compoundH202. H202.

a) 2(H2C2: C2); H2Br2 ~ 2C2; H2Br2!2H;2C2O3~2H;2C205. B) 2H2C4;

This meta water-salt soon resolves itself, in the next stage, into 2 mols. of water which are liberated, and the ortho water-saltH2O2. H202.

a) 2(H2C2: C2); H2Br2- 2C2; H2Br2: 2C2O3~2C2O3, B) 2H2C4;

which, by the loss of 2 mols. of carbonic acid, becomes finally converted into the dibromo-butyrate, as formulated above.

It is at this point that the interesting series of metamorphoses commences, to which allusion has just been made, but for the proper comprehension of which I require to submit first of all the analysis of a kindred and more familiar, but as yet perfectly unintelligible, series of reactions. The case selected for illustration and comparison refers to the characteristic deportment of the dibromide of ethylen on its being subjected to the alternate influence of hydrate of potash and bromine. Now the molecular changes attending the successive stages of this curious reaction may be described as follows:In the first stage, the dibromide of ethylen2H2C2; H2Br2 2C2; H2Bra transposes with the hydrate of potash, with production of the compound— H2O2.

2H2C2; II2Br2 - 2C2; H2O21

and bromide of potassium, under the influence of which the former molecule is speedily made to resolve itself into 2 mols. of water and the body2(H2C2: C2); H2Br2. 2H2C43

In contact with 2 mols. of bromine, this latter becomes then changed into the compound

2HC2Br; H2Br2 ~ 2C2; H2Br2, which, with the aid of a second molecule of hydrate of It is meet that I should now advert to a very interesting | potash, becomes quickly reduced to the bodyseries of transformations which certain descendants of the 2(HC2Br: C2); H2Br2. three varieties of meta-dibromo-pyro-tartrate are apt to 2HC4Br

SYNOPTICAL ARRANGEMENT OF CHEMICAL FORMULE, COMPRISING THE BROMINATED DERIVATIVES OBTAINED BY THE ALTERNATE ACTION OF HYDRATE OF POTASH AND BROMINE ON THE DIBROMO-BUTYRATE OF WATER. Dibromo-butyrate

H202.

a) 2(H2C2: C2); H2Br2 2C2; H2Br2 2H ; 2C2O3. B) 2H2C4;

Tribromo-butyrate

Bromo-crotonate7) 2H2C6;

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H202

Y)

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7)

Tetrabromo-butyrate

a) 2(C2Br2: C2) ; H2Bг2 — 2C2 ; HaBra: 2H ; 2C2O3. B) 2C4Brai

Tribromo-crotonate

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a) 2(C2Br2: C2: C2); H2Bra: 2H ; 2C2O3. B) 2(C,Bra: C2);

2C2Br2; H2Br2 - 2C2; H2Br2,

The prevention of smoke next received some notice from Dr. Wallace, and the operation of the law relating to that subject was shown to be somewhat anomalous in which, with the aid of a third molecule of hydrate of puddling furnaces within the city, which might give off Glasgow, inasmuch as a person might erect a hundred potash becomes finally transformed into the body2(C2Br2: C2); H2Br2. 2C4Br2;

dense volumes of the blackest smoke day and night, without the owner being interfered with, for the law could not touch him; but if the thousandth part of the smoke were emitted from a badly-fixed boiler, the myrmidons of the law would pounce upon the owner at once.

NEWS

In contact with a second pair of bromine molecules, this latter becomes then changed into the compound

By applying the preceding train of reasoning to the dibromide of allylen, which in the dibromo-butyrate is made to play the part of a halogen adjunct, the reader will not find it difficult to interpret the molecular changes which ensue on the dibromo-butyrate being subjected to a similar treatment. It will, therefore, suffice to append a list of the chief transition products with which, in the absence of the customary winding up, this paper is perhaps rather abruptly brought to a close.

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(CHEMICAL SECTION).

THE first meeting of the session of the Chemical Section of the Philosophical Society of Glasgow was held on the evening of Monday, November 10th, when Dr. William Wallace, F.R.S.E., delivered the opening address as retiring President.

After a few introductory remarks, Dr. Wallace spoke with some detail on the operation of the Adulteration Act, and the difficulties attending it so that convictions might be obtained in accordance with its spirit. He specially referred to milk and tea among the articles of food that are subjected to adulteration. The only cure for the anomaly of retailers of tea being subjected to the hardship of being severely fined for selling adulterated tea, though they were perfectly innocent of the fact that it was adulterated, would be to have each cargo of tea, as it arrives at port, examined by Government officials, who should have power to order the destruction of all tea which had been mixed with adventitious matter. Dr. Wallace considered that there could be no doubt that the Adulteration Act would greatly increase the number of professional chemists in this country. Already some of the gentlemen appointed as Analysts had exercised their vocation, not only in testing the samples submitted to them, but also in adding important facts to our knowledge regarding certain articles of food. He strongly urged the desirability of appointing, as Analysts under the Act, competent and experienced chemists having reputations to support, and making it worth their while to give attention to their duties, by giving them fixed incomes in addition to moderate fees.

at

Dr. Wallace dwelt at considerable length upon the chemical questions involved in the disposal of the sewage of large towns, and the conservation of the purity of rivers. There was probably no great town or city in the three kingdoms where the whole question of the disposal of the sewage had been so thoroughly discussed, or so perfectly understood, as in Glasgow, and there was perhaps none in which so little had been done. The local sewage literature was of great extent and value, but the citizens had hitherto been content to look on and witness the experiments conducted elsewhere, sometimes enormous expense, and the failures that had almost invariably attended the experiments. There were local gentlemen, high in office, who were in favour of the great Bateman and Bazalgette scheme of pumping and conveying the Glasgow sewage to the sands on the Ayrshire coast, for the purpose of irrigation, at a cost of something like £2,000,000; but he sincerely hoped that those gentlemen would study the subject further, and see for themselves the results of sewage irrigation elsewhere. For the Glasgow sewage an area of 25,000 acres, or nearly forty square miles, would be required for the Glasgow sewage if irrigation were to be resorted to.

After speaking of the various systems of sewage filtration and so-called purification-General Scott's, the A B C, and that by the use of peat charcoal, as practised at Bradford-Dr. Wallace said that a revised Pollution of Rivers Act would doubtless be passed next session, and that not unlikely it would be made applicable to Scotland as well as to England, in which manufacturers would be brought under a very stringent law; but, as long as the water-closet sewage was discharged into rivers, it would be ridiculous to impose penalties upon manufacturers for adding their comparatively trifling contribution of polluting ingredients. Dr. Wallace concluded his address by making some very practical remarks regarding the endowment of scientific research, a subject to which renewed interest had been imparted by the address of Professor Williamson as President of the British Association at its recent meeting at Bradford. He said it was disgraceful that in Glasgow, a city which owed so much of her wealth to chemical manufactures, there was no professor of technology, and that even the chair of chemistry was so miserably endowed that its occupant-one of the ablest and most industrious of modern chemists-was obliged to eke out the means of subsistence by commercial work which, though important enough in itself, might be performed equally well by men of far inferior talent and originality..

Speaking of analytical work, he said that, in this country especially, it had become an important branch of the profession, and that it had of late years attained a scientific precision which it never before possessed. It was not uncommon for analyses to be made for commercial purposes, and for a comparatively trifling fee, with greater skill and a higher degree of accuracy than was exhibited in a large proportion of the researches published in scientific journals; and it often happened that a chemist brought up in what might be called a strictly scientific laboratory was totally incapable of undertaking the simplest analyses with results that were of any practical use. Such knowledge, like every other kind that was valuable, was only to be acquired by hard work and great practice, but that fact made it impossible for an analyst having a large and engrossing business to devote any portion of his time or talents to the higher branches of chemical study. Other sub-divisions of chemical science led to the

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