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It will be remembered by those who have read the reports of the terrible explosion which occurred at Abercarn on September 11 last, that in consequence of the coal having

taken fire close to the main shaft at Abercarn and in the workings, and a direct communication between the upcast and downcast being determined by the explosive force which destroyed the parting doors, it was soon discovered that it was advisable to flood the colliery in order to quench the fire. It will be remembered, too, that the colliers who were fortunate enough to escape with their lives found their way out by the main winding shaft. The Abercarn Colliery has three shafts or pits-two downcasts and one upcast. The main downcast and upcast, which are 22 yards apart, are situated at Abercarn, and the other downcast is at Cwm Carn, a distance of a mile and a quarter in a direct line, and two miles underground from the upcast. As soon as the Abercarn portion of the workings was filled with water, the gas issuing from the coal and some of the products of combustion from the burning of the coal, and possibly more or less of the products of complete and incomplete combustion incidental to the explosion, were driven in the direction of the Cwm Carn pit, toward which the measures rise about 400 feet or a little over 2 inches per yard. After the flooding of the colliery was completed on September 16, when over 40 feet of water were in the two shafts at Abercarn-a large volume of gas, varying from 500 to 1500 cubic feet per minute, was evolved until the water was cleared out (about the middle of November) sufficiently low to admit of a current of air being drawn in the direction of the upcast shaft. On September 20th last I collected some of the gas issuing from the Cwm Carn shaft, which was covered with turf with the exception of a hole in the centre occupied by an iron pipe 11 inches in diameter, through which the gas escaped. On both occasions the gas was collected in glass tubes previously fashioned for sealing off the ends before a blowpipe flame-a double acting syringe being employed to cause the gas to fill the tubes by displacement. The analysis of the sample of gas collected September 20 is marked No. 1. At the time of collecting it 500 cubic feet per minute were evolved, the temperature being 58° F. On October 9, I again collected gas, the composition of which is given in No. 2-about 1200 cubic feet of gas per minute were escaping at the

time.

Composition of the Gas in 100 Parts.

Carbonic anhydride
Oxygen

Air Nitrogen

Hydride of ethyl

Marsh-gas

Nitrogen

No. II. 2'43 none

74.63

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No. I. 2'54 2.73 10°32

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The composition of the hydrocarbons present, othe than marsh-gas, resembled hydride of ethyl, but the analytical volumes did not agree well in No. I. On comparing No. I. gas with No. II. it is evident that the former contains a considerable proportion of nitrogen derived from atmospheric air, the oxygen of which had been used up to support the combustion of the fire-damp or the coal which was on fire. Owing to the plentiful supply of air which reached the burning coal previous to the colliery being flooded, it is possible that little if any carbonic oxide was generated, and the absence of this gas in No. I., in which it was carefully sought, seems to show that the incomplete products of the combustion of the explosive mixture (the fire-damp which gave rise to the explosion) had either in part been removed or so diluted with other gases that the carbonic oxide was present in quantity too minute to be determined in the process of analysis. The composition of No. II. is interesting. This consists doubtless of a mixture of blower-gases which found their way into the galleries through the channels and cracks in the strata, and the gases evolved from the The latter gases working face cr other exposed coal. would be naturally of similar composition to those which escape under ordinary conditions of pressure and temperature from a lump of coal exposed to the atmosphere. In previous papers "On the Gases Enclosed in Coal," Chem. Soc. Fourn., 1875-6-7, I have pointed out on more than one occasion the curious fact that nitrogen escapes from coal in a vacuum at a proportionally quicker rate than any other gas. The flooding of the mine entirely cut off the supply of air and consequently no nitrogen could find its way into the galleries, admitting the possibility of the oxygen being used up. It is evident, therefore, that the percentage of nitrogen in No. II. is high, and that this circumstance points to the probability of its escaping from coal under ordinary conditions in the same manner as it does in a vacuum. Before No. II. sample was collected it will be seen from the analysis that all the air had been swept out of the workings by diffusion with the gases evolved from the coal, and long before the expiration of the nineteen days which elapsed between the collection of No. I. and No. II. all the products of combustion would have been removed. During the nineteen days an average of more than 1,000,000 cubic feet of gas was evolved each day, equal to the cubic contents of a large gallery or heading 5 miles in length. My thanks are due to Mr. Pond, of Abercarn, for the facilities afforded me in the collection of the gases and for

his kind assistance.

The Laboratory, Cardiff, January 6, 1879.

ANALYSIS OF POPPY PETAL ASH.

By C. J. H. WARDEN, F.C.S.

ANALYSES of the organic constituents of poppy petals have been made by several chemists, but poppy petal ash has not hitherto, as far as I am aware, been examined. Before giving results of the analysis of the ash, a few remarks on the use to which poppy petals are put in the Government Opium Factories in Bengal may be interesting. In the manufacture of opium for the China market"Provision Opium"-it is customary to envelope the soft opium in a shell composed of poppy petals technically termed "leaves."

The petals are usually collected by noon on the third day of the flowers' expansion, and Mr. J. Scott thus describes the process:-" They clasp the petals at the base with the forefinger and thumb, gently drawing them upwards, and tightening them over the apex of the capsules, when the matured petals at once disarticulate or detach themselves. There is thus no tearing or straining of the petals, and no loss of juice from the disarticulated surfaces."

"Manual of Opium Husbandry," by J. Scott.

28

The Uric Acid Group.

The petals are then made into round "leaves" by spreading | them on gently heated earthen or iron saucers, covering them with a moist cloth, and applying firm pressure by a damp pad. "Leaves" vary in diameter from 6 to 12 ins., and in thickness from o'5 to o'025 of an inch.

At the Patna Opium Factory 10 ozs. 94 grs. avd. of "leaves are used for making the shell of each cake. The "leaves" are agglutinated round the opium by a 50 per cent mixture of opium in water.

Mr. Scott calculates that the annual consumption of poppy petals is upwards of 16,000 maunds (one maund equals 100 lbs. troy), to compose which the entire petals of no less than 4,710,400,000 flowers are required! During the season 1869-70 the Bengal Government spent £10,235 on leaves for the use of one factory. From the above short account of "leaves" it is evident that the poppy petal is an article of considerable commercial value.

The ash was prepared for analysis in the usual way, and was of a light grey colour, and effervesced with acids. An aqueous solution gave indications of the presence of SO3, P2O5, Cl, and K. All the determinations were by gravimetric methods:

100 Parts of the Ash Contained.]

Ferric oxide, Fe2O3
Aluminic oxide, Al2O3
Magnesic oxide, MgO

Calcic oxide, CaO
Potassic oxide, K2O

Potassic chloride, KCI

Sodic chloride, NaCl

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0'9701 4'4311 8.4711 32.9926

9.7078

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Sulphuric anhydride, SO3

Phosphoric anhydride, P2O5..
Carbonic anhydride, CO2
Silicic anhydride, SiO2

Sand ..

Charcoal

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{CHEMICAL NEWS

January 17, 1879.

containing a certain amount of putrescent substances cannot have a great influence on the health of the inhabitants of the town, and remarked that even in science this question is nearly an open one, as it has been only partly discussed. Indeed, it is a question if contaminated water, used for domestic purposes, can do any harm. The Professor remarked, also, that sometimes, for instance, in consuming various cheeses we introduce at one time a quantity of putrescent matter into the stomach, which would not be detected in the annual amount of water consumed, containing a large quantity of organic matters. The analyses of the Neva water (by Professor Trapp) show that it cannot be called bad water :

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M. Bertenson could not agree with the Professor. He remarked that oxygen is very important in water, and certainly the more organic matter is present in the water the less it contains of free oxygen.

The committee decided to inspect the cemetery, and take some water for analysis from the small river, and then agreed to inspect also one of the bodies which was buried the first on this ground. The conclusions of the committee will be of some interest, as there is not much agreement between the members concerning the question discussed.

Percentage of the ash after deduction of the unessential constituents, carbonic anhydride, sand, and charcoal :—

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THE St. Petersburg town council organised a committee for the discussion of the following question:-About seven miles from the town a new cemetery was opened some years ago. A small river runs from this place into the Neva, some eight miles above the town. It was found that this small river is entirely contaminated by the decomposition of the bodies. Owing to this inconvenience many propose to close the cemetery. The discussions which took place in the sitting of the committee on November 23, 1878, are rather interesting, as the sanitary improvements of the town are still considered secondary questions.

M. Borodin, Professor of Chemistry, thinks that water

THE URIC ACID GROUP.

By SAMUEL E. PHILLIPS.

As Mr. P. T. Main has advanced some new views of urea, uric acid, and their derivatives, it may interest some students of chemical philosophy if I give the substance of a paper read before the British Association of 1877, " On the Principle of Uric Acid Genesis."

"As the vast and complex researches of Liebig, Strecker, Baeyer, and others have now culminated in the studies of M. Grimaux, it is thought to be high time to trace herein the plain indications of law, order, and symmetry in lieu of empirical confusion." The author refers to a paper on the constitution of uric acid (CHEM. NEWS, vol. xxxii., p. 209), and now maintains that a clear view of the chemical laws involved in -2HO, under varied conditions, will supply the key to unravel the endless empirical confusion.

Starting with eight acids, it is maintained that under the combined influence of heat, time, and pressure that all these, and some others, act similarly upon urea, and condense with successive eliminations of -2HO, in proportion to the strength or duration of the applied conditions:

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NEWS

some blanks, which may easily be attained in the future, and that these eight series may be thus epitomised, assuming I equivalent of acid in each case :

+ Urea-2HO=(CO)2RH3N2=the R urea (a)
-4HO=CyRHN the cyanamid (b)
+2Urea-2HO=(CO), RH,N, the di-urea (c)

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=

-4HO=(CO)2CyRH5N3=the pseudo-uric acid (d) -6HO=Cу2RH3N2=the ultimate (e)

It is remarked that these uric acid ultimates are not strictly such, and the two extensions of variety are excluded from the brief terms of the paper:-First, certain obscure cases where these radicals are affected by reaction with ammonia - 2HO, as in hydrazulmoxin and hydrazulmin; secondly, the more complex forms of ureide condensation obtained by M. Grimaux, which all, nevertheless, prove to be grand illustrations of the same definite It follows that all the (a's) are normal ureas, though often associated with confused names in their empirical discovery; that all the (b's) are R cyanamids, though not at all recognised as such, and some of them are called ureas; that the ureides or di-ureas have three stages ending in uric acid and its other analogues; that the law of elimination has three aspects:

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I am much pleased to find that I am not alone in entertaining the cyanamid character of uric acid; but the idea of including urea in the same category, as a derivative of uric acid, is certainly a confused and illegitimate sketch of hypothesis.

The ammoniacal character of urea is established beyond question; its amide dedoublements and their basic characters admit of no other explanation.

M. Dreschel, in obtaining several varied cyanamids, notates one as "the hydrochlorides." It is therefore clear that he might have obtained the hydrate. Besides, hydrates of dicyanamid and others are known, but surely no one expects to find them ureal.

Mr. Main falls into a mistake, which his notations ought to have corrected; but, alas! they are only fitted to mislead. Allantoin is not a derivative of "glyoxylic acid," as may be seen thus:

Glyoxalic acid C4H104,0.HO=glyoxalyl urea + urea -2HO=(CO)2C4H2O¡Í ̧Ñ2 (a) -4HO=CyC1H2OHN (b)

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+2 urea -2H9= (CO) CH2O,H ̧Ñ4 (c) -4HO=(CO)2CуC4H2O1H5N3 (d) -6HO=Cу2C4H104H3N2 (c)

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(b) As urea -2HO becomes cyanamid, so glyoxalyl urea - 2HO becomes glyoxalyl cyanamid."

(c) Is the hypothetical first stage of the di reaction. (d) The second stage is allantoin, and the formula o production is precisely that given by the discoverer, M. Grimaux. It also corresponds with M. Grimaux's Pyruvil in the pyruvic series, or with my pseudo-uric acid in the tartronyl series. (e) Is the ultimate miscalled "mycomelic acid" and the perfect analogue of uric acid.

One word more as to the bizarre character of these misleading notations.

The discoverer of "melid acetic acid" thought it was an aceto body, and that it was an acid, and hence the terminal (COOH) so fashionably characteristic of acid types! Of course the pretence is that these structural or graphic portraits are intended to delineate certain features of genetic or analytic behaviour in the compounds. The plain fact is, however, that it is a mischievous device of wanton hypothesis, and hence our exposure of the true nature of that body, as containing no acetic acid in its genesis, and no acid behaviour in its derivatives. It is a substituted mellamine base! (See CHEMICAL NEWS, Vol. xxxiv., p. 13.)

When M. Grimaux speaks of glyoxylic acid he means glyoxalic acid, and his notations correspond with his remarkable synthesis of allantoin: but Mr. Main, rightly estimating the total elements of glyoxylic acid, gives allanturic acid as one of its derivatives, which is a double mistake. First, as a matter of chemical fact; and, secondly, as a matter of notational display.

Allanturic acid is "glyoxalyl urea." Why, then, justify its early misnomer by an acid notation ending in (COOH) Glyoxylic acid

Allanturic acid

(CHHOHO [COOH (CHHONHCN 1 COOH

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(a) is tartronyl urea, (CO)2C6H1O6H3N2. Both (a) and (b) are given with the acid terminations to correspond with tartronic acid; but it is quite overlooked that (b) belongs to another acid series, for it is known to be a "malonyl urea."

How, then, does it happen that so many amides should be called acids? The answer is plain, and the parentage is clearly traceable to a mistaken hypothesis of the early discoverers, which is grossly perpetuated to this day. They noticed among these bodies a tendency to combine with or to assimilate metal ingredients, and the notion was that the relation subsisting was that of acid and base.

It is, of course, familiar that many hydrocarbons have a tendency which is notably typified in acetylen; and we now find that the same tendency is frequently evinced among amides; but the wonder is that modern chemists should be so slow in establishing a just discrimination.

Were we to imitate Mr. Main's ureal hypothesis, and contend that ammonia was an acid, and that the amides of Zn, Cu, or K were its basic salts, the idea would necessarily be scouted; but the same principle is largely and widely indulged in throughout the modern types of organic chemistry; and we constantly read of amido acids, and see their terminal (COOH) graphically displayed, while the context in so many cases reveals the fact of their basic characters, as seen in their "hydrochlorides," their sulphates, nitrates, and other salts.

30

Rozan's Process for Desilvering Lead.

{

CHEMICAL NEWS, January 17, 1879.

I care not to follow Mr. Main when he seeks to paint | tile sulphur and the sulphur contained in the ash. Perhaps the lily, and to improve his bizarre notations by atomicity it might be interesting to the members if Mr. Pattinson equations and "more symmetrical" portraits of the atomic would explain how the amounts of these latter are deterdispositions. But the body selected for all this display mined. is wisely chosen from the least understood of chemical compounds, viz., the amorphous substance called "hydrazulmin."

It may or may not be a definite chemical body; but as I have done my best, in a known and legitimate way, to arrive at some faint à priori understanding of its genesis and relations in a yet unpublished "Study of Ureide Derivatives," it may be well to compare notes as to our methods of investigation. One is playing with skittles, and can place them in any position, only controlled by certain laws of the game, such as the atomicity rules, &c. The other is rather a student of the actual chemical forces involved, and has comparatively a very limited number of pieces. He can only place on the board definite or well known radicals, and these only in certain limited modes of relationship, while from an infinitude of "residues" he is utterly debarred.

With one it is an easy matter to build up on paper a melid-acetic acid, or an allanturic acid, with wrong materials; with the other these feats are simply impossible. One is so confidently assured that he can open out the condensed types to graphically exhibit the internal play of atomicities, and go yet further in the Frankland school to "more symmetrical" pictures. The other has to retire in all humility, simply confessing inability to either execute or understand such works of art.

"We have referred to the uric acid analogues as ultimates. That term, however, admits of some qualification, because by another mode of reaction it is possible to reduce the radicals of the varied acids, and in that respect to realise more ultimate compounds. "Mycomelic acid," Cy2C4H104H3N2(a) (a) +H3N-2HO, hydrazulmoxin,Cy2C4H2O2H2(NH2)N2 (b) (b) +H3N- 2HO, hydrazulmin,— Cy2C4H2OH(NH2)2N2 (c) It only remains to notice that this hydrazulmoxin is identical or isomeric with Mr. Main's "azulmic acid." That in each of these stages of reaction one equivalent of ammonia is added is a chemical fact beyond question; and that each stage implies a theoretical tendency to - 2HO is a principle I have tried hard to exemplify, and need not here repeat the grounds, while gladly referring to the actual facts of analysis in confirmation.

PROCEEDINGS OF SOCIETIES.

NEWCASTLE CHEMICAL SOCIETY. General Meeting, November 28, 1872.

Mr. R. C. CLAPHAM, President, in the Chair.

THE minutes of the previous meeting were read and confirmed.

The following were elected members:-Mr. Walter Weldon, Dr. Bernard Mohr, Mr. John Watson, Mr. Thos. Campbell, Mr. John Hope, jun., Prof. R. W. Atkinson, Mr. Mayfield, Mr. J. W. White, Dr. H. E. Armstrong, Mr. T. Crawford, Mr. W. G. Strype.

The following name was read for the first time :-Mr. John Cliff, Runcorn.

The PRESIDENT-Our first business, gentlemen, is to proceed to the discussion on Mr. Pattinson's paper, "On the Quality of the Small Coal used on the Tyne." It is a very valuable paper, especially as regards the amount of sulphur contained in the ash. I do not remember having before seen results set forth to show both the vola

Mr. PATTINSON-It is very quickly done. The total sulphur is determined in the usual way, by oxidation; then the amount remaining in the ash of the coal is determined, and the difference of these two amounts gives the volatile sulphur. The sulphur in the ash is retained by virtue of the lime which the ash contains, which probably existed originally as carbonate. I may perhaps mention here the method used to determine the total sulphur in the coals. The old method, by heating with strong nitric acid and evaporating to dryness, is very incorrect, never yielding more than a fraction of the sulphur really contained in the coal. The method by deflagration with nitre and salt is very correct when carefully done, but it requires great care, both in the deflagration and in the subsequent precipitation of the sulphur as barium sulphate. The method now used, however, is very much simpler than any of the old ones: a weighed quantity of the coal or coke (about 20 grains) is mixed with one and a half times its weight of slacked lime, moistened slightly with water, and then heated in a muffle at a red-heat. The carbon burns off, and the sulphur is converted into calcic sulphate, which is then dissolved in hydrochloric acid, and the sulphuric acid precipitated in the usual way. Mr. H. L. PATTINSON-What is the reason that the method of treating with nitric acid is unsatisfactory? Mr. J. PATTINSON-Probably a portion of the pyrites is covered and protected by the coal, even when it is very finely pulverised.

The PRESIDENT-If no member has any more remarks to make we will proceed to the discussion on Mr. Dunn's paper, "On Indicators in Alkalimetry." I do not know if his paper. Mr. Dunn has anything further to add on the subject of

Mr. DUNN-I have not done anything more in the matter since the paper was read. I may just mention, however, that aurin does not keep quite so long as litmus. It will, however, keep for two or three months without alteration, and the preparation of the solution is so easy that it can be made afresh every two or three months with very little trouble.

The PRESIDENT, in calling on Mr. Cookson to read his paper, On Rozan's Process for Desilverising Lead," said, I had the pleasure of going down to Messrs. Cookson's works, at Willington, a few weeks ago, and I think I have not for a long time been in any works which were more interesting, both from a chemical and a mechanical point of view. The handling of large quantites of lead is done almost entirely by hydraulic machinery, which I have no doubt saves a large amount of money formerly spent in wages for hand labour. The paper to come before us to-night is one of very great interest, and perhaps, if we say anything about it now, it must be to express a kind of regret that a patent is likely to come into operation which may do away with the classical process of Mr. H. L. Pattinson-a process for which the North of England has long been justly celebrated.

"On Rozan's Process for Desilverising Lead," by Mr. COOKSON. In attempting to describe the leading features of the Rozan system of desilverising, I must ask you to bear in mind that in principle it is in most respects identical with the well-known process of the late Mr. H. L. Pattinson, always excepting that in the former case cranes and steam supersede the more expensive system of manual labour employed by Mr. Pattinson. In both cases, however, the whole working depends on the fact that as melted lead cools the first-forming crystals contain less silver than the portion remaining liquid, and that in the usual way of working by thirds this exists to the extent that when two-thirds of a given quantity is in crystals and one-third liquid, the two-thirds will actually contain only half the quantity of silver that the one-third or lesser quantity does. In the Rozan system steam is

might give a little more account of. When I saw Mr. Cookson's works the condensation appeared very perfect and free from escape.

Mr. COOKSON-It is not a point of much importance whether the condensers are air-tight or not, because we have a draught at the far end, so that there is always an inward suction. In practice we find that in the last chamber there is little or no settling. I have sometimes extra-opened the door and gone in, but could never observe any. thing except steam in the state of fog or cloud. The oxides of antimony and copper are partly skimmed off the melted lead as dross, and partly condensed as fume in the chambers. The fume near the furnaces contains a larger quantity of these oxides, and as it gets further from the furnace it approaches more and more nearly in composition to pure oxide of lead, thus confirming an old dictum of lead-smelters, that oxide of lead is more difficult to condense than the oxides of the accompanying metals. One thing I did not mention, which has indeed nothing to do with the subject of the paper, but is simply a mechan. ical arrangement-our system of cranes is very perfect. From the time when the crude lead enters our works to the time when it makes its exit as "market lead" it is hardly ever touched by hand, but lifted from place to place entirely by hydraulic cranes, which costs very much less than if it were lifted by hand.

used with a double purpose, one of which is mechanical | and the other chemical. The mechanical effect is to boil up and violently stir the melted lead, thus preventing any setting on the surface; and this boiling of the steam through the lead as it cools causes a regular crystallisation, and an easy and perfect separation of the liquid from the crystals when the proper stage is reached. The chemical effect is due to the oxidising action of the steam on the antimony, copper, iron, arsenic, and other neous metals, which, being converted into oxides, are either skimmed off or carried away with the escaping steam, and afterwards allowed to settle in the condensers. This chemical action fulfils so good a purpose that the Spanish rich silver leads are desilverised without any previous calcination, and an unusually pure market lead is produced from them. Even in the case of Greek lead only a partial calcination is required, as experience shows that a portion of antimony, equal to about per cent, existing in the original silver lead, is an advantage, inasmuch as this small quantity of antimony has a remarkable effect in reducing the quantity of lead oxides formed, Without absolute proof it may be premature to speak of any chemical action, as it is possible the whole of the oxidation is due to the mechanical exposure of the molten impure lead to the influence of the atmosphere, assisted by the air carried into the pot by the steam; but I am strongly of opinion that a chemical action actually takes place. The leads most suitable for the steam process are of a similar class to the already-mentioned Spanish rich silver leads, containing from to per cent of foreign metals, of which antimony generally constitutes fully two-thirds of the quantity. In the old Pattinson process those extraneous metals are eliminated as far as possible by a previous calcination, the charges sometimes requiring forty-eight hours in the calcining furnace in order to fit them for the pots. In the Rozan system, however, this calcination is dispensed with, and the lead as it comes out of the smelting furnaces is used direct by the desilverising apparatuses.

Having described the working of the plant, I will put before you as shortly as I can the advantages and defects of the Rozan as compared to the Pattinson system as carried out in our works for a great number of years. The advantages the Rozan system possesses are—

1. The entire saving of the cost of calcining all ordinarily hard leads, and in the case of extra hard leads, such as Greek lead, a very large saving. 2. A cost for labour not exceeding one-fifth. 3. A cost for fuel of about two-fifths. 4. A saving of one-third in the oxides produced, which advantage any lead manufacturer will fully appre

ciate.

Its defects are

1. A large capital outlay.

2. A constant expense in repairs and renewals.

The repairs are only a small matter, but until lately the cost of renewal of pots was a very serious and heavy item: it is one which by observation and care we have been able very considerably to reduce. In 1876 pots cost us over 3s. per ton of market lead; in 1877 it came to 28. 2d.; and this year, so far, the cost has been further reduced to Is. 4d. per ton.

On the whole, the advantages are very considerably greater than the defects of the Rozan system; and I can confidently assert that our firm has every reason to be satisfied with having adopted it.

The following is a table showing silver assays of twelve crystallisings taken from an average of 350 operations: Ounces per ton of lead.

570 315 202 112 62 33 19 10 5 2 1 14 dwts. The PRESIDENT-Would any member like to ask Mr. Cookson any questions about the paper? Mr. Morrison has referred to condensation, and it struck me that that was a point which, at the present meeting, Mr. Cookson

Mr. GLOVER-In blowing the steam through is there any chemical decomposition of the steam, or is the action simply mechanical ? Are the copper and antimony oxidised by the steam, and the oxides volatilised, or carried off mechanically?

Mr. PATTINSON-To a chemist the most interesting point in the process is that which has just been mentioned by Mr. Glover. I am inclined to think that at such a temperature the copper would not be volatilised. Could Mr. Cookson tell us the composition of the fume condensed near the crystallising pot? I think that as the oxides of copper and antimony accumulate on the top, they are most likely to be mechanically carried away to the condensers. The question is, is the steam decomposed, is hydrogen produced, or is the oxidation due to the atmosphere?

Mr. COOKSON-I think it is due principally to the free oxygen which is always contained in small quantity in the steam, and that the oxides are then carried away by a purely mechanical action.

Mr. B. S. PROCTOR-Have you ever had any trace of hydrogen?

Mr. COOKSON-I have put my nose into the condensers, thinking that if hydrogen were produced there would be a certain quantity of arseniuretted hydrogen formed, but I have never smelt any. There is a trace of sulphur found in the condensers, but I never smelt any sulphuretted hydrogen.

Mr. H. L. PATTINSON-Have you ever tried air instead of steam?

Mr. COOKSON-It is included in the patent, but it increases the quantity of oxide of lead formed very greatly. Mr. GIBB said, it appeared to him that the action of the steam was purely mechanical, not chemical, and that the process was merely the Pattinson process with improved mechanical arrangements.

The PRESIDENT wished to remind Mr. Gibb that most of his objections had been already answered by Mr. Cookson in the paper itself.

Mr. COOKSON-I so far agree with Mr. Gibb that I often call the process "Mechanical Pattinsonisation." The steam may perhaps be described as a vehicle for conveying the oxygen of the air in limited quantity to the lead.

Mr. PATTINSON-Or a valuable means of getting the mechanical effect of air with a smaller proportion of oxygen.

Mr. MORRISON-The steam protects the lead?

Mr. COOKSON-No; for if we work soft leads we find, with all our care, that the quantity of oxides produced is largely increased.

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