but as far as examined they are different mineralogically from the so-called meteorite.

The typical occurrence of tephroite and hausmannite is in contact-metamorphic deposits. No limestone is present in the vicinity of Alum Rock Canyon and none was found in the boulder. Limestones of Franciscan age are known at various places in the Coast Ranges, but they are unmetamorphosed.

Although some doubt is attached to the original occurrence of this manganese ore, the presence of tephroite and hausmannite points to the high-temperature nature of the deposit. The rhodochrosite is undoubtedly a hydrothermal mineral, and the psilomelane doubtless was formed by meteoric waters at a very late period. The pyrochroite is intermediate in age between the rhodochrosite and the psilomelane. Was it formed by meteoric waters or by hydrothermal solutions? This question can not be answered definitely, but it is believed to have been formed at a late hydrothermal stage. It is altered to a later hydrous manganese oxide, and so is unstable under oxidising conditions. In fact, specimens alter when exposed for several days. The presence of a large amount of water-Mn(OH)2, H2O 2013 per cent-is no proof that a mineral is formed by meteoric waters. Such is believed to be the essential history of this interesting deposit or rather remnant of a deposit, though a number of questions cannot be settled for lack of sufficient data. The existence of this boulder makes it probable that some, if not many, of the manganese deposits of the Coast Ranges of California are of high-temperature bydrothermal origin. The prevalence of psilomelane may be accounted for by subsequent alteration of the hydrothermal minerals by meteoric water.-American Journal of Science, xlviii., 443.

=

ZIRCONIA.

STATEMENT AS TO ITS INDUSTRIAL DEVELOPMENT.

ZIRCONIA, the new refractory (about which so much was written during the war), was discussed, from the point of view of its development in industry, in a paper by Mr. H. E. COLEY, of London (which was read by Mr. Ramsden), before the members of the Birmingham Metallurgical Society at the Chamber of Commerce, Birmingham, on Thursday, December 18.

Mr. F. C. A. H. LANTSBERRY, F.I.C., who presided, urged that the metallurgical and ceramic industries were greatly in need of better refractories.

The AUTHOR said if one assumed that zirconia had descended from the pedestal of the rare earths lists, and that literature was correct and that it was the almost ideal refractory material, why was it not largely used in the metal industry? The commercial man said the cost was too high; he was not, however, concerned with the statements that zirconia formed carbides and nitrides readily, and indulged in other complex reactions only seen within a chemist's beaker. The two principal sources of zirconia ore were the oxide of zirconia plus gangue, and zirconia silicate known as zircons. There bad not, as yet, been devised a process with a cost production figure low enough to warrant pure zirconia oxide being used for refractory bricks in the furnaces, and therefore it was improbable that pure ZrO2 refractory bricks would be available for the metal industry. It was obvious that the ZO2 must be cheapened either by leaving some of the impurities with it or adding other materials of an inoffensive character. Showing samples of zirconia which had been through an operation for the removal of the iron and free silica (and which had a breaking down point under heat at a temperature of 2300° C.), the author said the whole question of the use of zirconia on a large scale and for heavy furnace work depended on the question of cost. Given a brick having a softening point of 2300° C. and none of the objectionable qualities of other refractories, could the metallurgist afford to use it? Zirconia was somewhat like a sharp sand, and the problem of plasticity had been largely solved. Zirconia in common with most other refractories could be influenced as to its shrinkage by the addition of grog, i.e., pre-burnt and ground zirconia. The essential point was that the grog should have been fired to the same temperature as that to which the bricks were to be fired. The firing temperature was not governed by the

Manganese (per cent).

Silicon (per cent). Solution in

Sulphur (per cent).

aqua regia.

Single evapora

oxidation.

tion only.

finish.

Nickel
(per cent).

Dimethylglyoxime

separation and cyanide titration.

"T

issued, but will serve in conjunction with them as a guide for firms doing work for the War Office and others. The Superintendent wishes it to be made clear that the homogeneity of the bulk of standardised turnings represented is not in any way guaranteed by the War Office. The homogeneity has, of course, been fully verified by the firms who provided the bars and by Messrs. Ridsdale and Co.

(Issued from Headquarters, 3, Wilson Street, Middlesbrough, under the auspices of the body of co-operating Analysts).

3'36

melting-point of the material but by the temperature of employment. The grog firing temperature was determined by the kiln firing temperature, and the kiln firing temperature was determined by the temperature of the furnace in which the zirconia shapes were going to be worked. It was worthy of note that there was not any appearance of the hackly fracture one would expect from the addition of grog, except where vitrified grog had been added, and then these granules were a source of weakness, not strength. The ground grog completely united

the raw material, and a homogeneous and plain structure results which tended to strength. The gas furnace was suitable for the firing of zirconia brick shapes. Much had been said, observed the author, about the formation of carbides of zirconia during firing, but there was not any evidence those carbides formed below fusion-point. The mistake bad probably arisen on account of the curious capacity of zirconia to absorb carbon. Black bricks could be obtained by firing the zirconia bricks in a strongly reducing atmosphere, carbon monoxide being freely available, with the result that carbon deposited in the zirconia bricks gave a black colour. That colour might be completely removed by firing in an oxidising atmosphere.

The point had been raised-Could the zirconia material from which the various shapes were made be used in situ ? If the material could be shaped to the furnace requirements on the spot without the manufacture of special shapes the cost would be materially decreased. The answer was that that could be done, but it must not be expected that the zirconia material was going to set under such conditions without cracks appearing. With adequate preparations a workable job could be obtained. A highly finished zirconia built furnace must be properly designed in sections, made in those sections baked separately and accurately fitted together. The position of zirconiawhich the war brought forward and had held back-was to-day as follows:-A zirconia material could be produced which so treated could be moulded into any suitable shape; the shapes could be baked to present a workman. like finish and surface, and when so baked the shapes had a melting-point of not less than 2300 C., a low coefficient of expansion; a low conductivity; a resistance to slags better than other refractories; the property of being heated and cooled alternatively and rapidly without deterioration; and a capacity to resist very great pres sures cold, and a greater pressure hot than other refractories.

As to zirconium as a metal and an ingredient in alloys, he could not give any useful information because the effects of the results obtained were not yet established. The work was embryonic. During the war we were told that the great German guns were made of zirconium steel. Our American Allies found out all about it quickly, and after that there was little news. Ferro-zirconium was made and could be made, and some day the real inwardness of the application of zirconium as an alloy would be established. But he asked them to remember that if it was an ingredient in the manufacture of German armour plates, and it might have been, it could not be found therein. Released from its bondage with oxygen it was a wayward and difficult material. If it could not have its oxygen it would take nitrogen in exchange, or silica. In short, it was an excellent scavenger, and therein perhaps was its ultimate destination. The production of ferrozirconium was, in fact, only the beginning and not the end of the matter.

DISCUSSION.

Mr. BRADFORD thought the chief disadvantage of zirconia for commercial use lay in the question of cost. Were there good supplies in Brazil? The extraordinary advantages of zirconia over the ordinary well-known refractories were so much greater that even an enormously higher initial cost might in the end be the more profitable, although the difficulty would be to make manufacturers realise that. He believed that a semi-purified zirconium ore would be adequate for ordinary commercial purposes.

Mr. H. HAYES believed the earth, zirconia, would be a great improvement on present refractories, most of which gave way, and caused delays, in the furnaces for the melting of nickel and nickel-silver alloys.

Mr. A. E. BROUGHALL Commented upon the wonderful properties of the refractory, and urged that if it did what was claimed cost would not prevent its use. Cost did not restrict the use of high speed steel.

Mr. A. BRAZINET enquired how many heats with brass could be done with the same crucible.

Mr. J. E. LESTER said he wanted to see where this rare earth was leading-whether its use was likely to become a commercial proposition, or whether it was to be merely academic.

Mr. RAMSDEN, in reply, said the cost of zirconia was not anything like double that of the other retractories, while the life of it was probably ten times greater than most, and four times greater than the best. The linings of crucibles would be of zirconium material, not of zirconia alone; the mixture gave a longer life. All the severest tests possible with other refractories place zir conia easily in the predominant position; in many instances it remained intact when other refractories gave way repeatedly. The cement was of the same material as the bricks, and applied wet a perfect bond was obtained. Zirconia was porous to water but not to salts, and they were not aware that it absorbed metallic fumes. There was no shortage in Brazil of the zirconia earth. Spraying zirconium preparation on fire-brick was not effective; what was wanted was a nice working face on the lining. With the material plastic, cracks after six heats were easy of repair; there was not that glazing as with ordinary refractory material. It was not necessary to line the lids. To the author and Mr. Ramsden a hearty vote of thanks was passed.

RECONSTRUCTION OF A SULPHATE OF AMMONIA PLANT.

A PAPER on the reconstruction of a sulphate of ammonia plant was read by Mr. Joseph Poulson, Works Chemist at the Stafford Corporation Gas Works, on Thursday, December 18, before the members of the Midland Junior Gas Association at the Council House, Birmingham.

The Author pointed out that the previous plant was badly damaged by subsidence. Regarding the re-erection of the plant, he said the sections of the square still were thoroughly cleaned, and the threads of all bolts and studs run down with a die nut.

The erection of the stills was then proceeded with. The jointing material used consisted of two parts glaziers' putty, one part vulcan cement, one part red-lead mixed with boiled linseed oil, and in this a soft cotton string was embedded. The lining still consists of cylindrical body, shallow domed top, conical bottom, and inlet and outlet pipes. A 6-inch sludge outlet pipe and valve were fitted to the conical bottom and the pipe led into the spent liquor pits at the back of the house.

The new heater is 3 feet diameter by 8 feet high, and is of cast-iron throughout. It consists of flanged cylindrical body, and fitted with flanged cap-shaped ends. The waste gases pass around 5-inch heavy cast-iron pipes, each end being jointed in sockets cast on a diaphragm plate, which is bolted between the end and body of the heater. The liquor is heated on its passage through the inside of the pipes.

The sulphate store was lead lined, namely, bottom and sides, the latter to a height of 10 feet, all joints being well lead-burned as laid. By carrying the lead bottom up to the height of a foot around the sides, this enabled a thinner lead to be used for the side sheets, which are burned to the lead floor. The lead was solidly worked into the channel previously made, and this would carry away any drainage that may occur from the store. The floor sheeting was continued to the saturator, &c., staging, and carried up the wall on the two sides as in the store. The saturator pier was lead covered, and the mother-liquor well lined, the latter with 10-lb. lead. Around the other sides of the platform wooden rolls were made to a height of ten inches, and the lead sheeting of the floor worked over these. The joints were burned with a fine oxy.coal gas flame. In this manner the floor of the stores and staging constituted a continuous tray, drained by means of the fall given to the floor, and the channels into the mother-liquor well, which has a capacity of 150 cubic feet.

The saturator is of the open type, having a well for ejecting, the size being 4 ft. 9 in. by 3 ft. 6 ft. by 3 ft. 4 in. deep, exclusive of well. The body is formed from plates 1 inches thick, with an apron of 1 inches, and the bottom and well of 1 inches lead. It is made of the best refined Pattisonian process chemical plate lead, with a minimum of seams, special attention given to the strengthening and webbing where needed to ensure its keeping shape, and all is securely timber braced. The well is encased in a strongly bolted pitch pine cradle, the saturator sitting solidly on same.

The saturator is fitted with double detachable ammonia pipes, detachable acid and steam pipes, detachable steam ejector, man-hole and man-lid, waste gas outlet, and flange. With this type of saturator not only can the salt be ejected, but, being of the open type, can be adapted to hand fishing should the ejector need repairs or renewal. The double ammonia pipes are advantageous, both for long life and being carried along the back and two sides give that equalised distribution of the ammonia gases so desired. The perforated (leaden) steam-pipe has proved useful for dissolving the crystals that form round the ammonia pipes and saturator sides after the plant has been shut down. Also, by putting the steam on at intervals for balf a minute when the saturator is salting, a better contact is given to the ammonia gases with the acid, and the salt is blown to the front of the saturator into the well. A steam ejector lifts the mother-liquor from the motherliquor well into the saturator.

The dryer is of the steam-driven type, with lead-lined steel shell and perforated copper basket of 48 inches diameter, 16 inches deep, with hinged copper doors fitted in the bottom. Through these the sulphate is discharged into the shoot below. The dryer is suspended on cast-iron standards which are bolted to a cast-iron bed-plate, and this, in turn, fixed on two larch timbers of 10 x 10 inches section, directly over the mother liquor well. The liquor extracted from the sulphate is conveyed through a detachable cast-iron bend into the well.

The waste gas condenser was made of a straight run of 18-inch cast-iron spigot and socket pipes with ordinary run lead joints. Flanged pieces were used at either end, and these were drilled to receive flanged and socket pieces for the inlet and outlet pipes. The cooling is effected by water continuously pumped along the entire length of the condenser through a 13-inch perforated pipe.

The waste gas purifiers were built in concrete at the front of the house, the base measuring 41×21 feet and having a thickness of 12 inches, and reinforced with expanded metal. Side walls were cast to a height of 2 feet 6 inches, and a central wall gave each purifier an internal measurement of 18 feet square. The supporting walls for the purifier grids measured 8 feet square and were built of 9-inch brickwork. Spaces were left in the brickwork so as to give extra distributing area for the waste gases.

New steam piping was installed throughout, and a new pressure reducing valve fitted to the branch leading to the stills. A Wilton automatic spent liquor valve was fitted to the main still. The coupling up of the various make-up pieces completed the re-erection of the plant. The covering of the stills with non-conducting composition is now in progress.

Improvements are to be observed in the working of the plant. The increased efficiency of the heater and main still have resulted in a decided economy of steam, as a waste liquor was got practically free from ammonia with a pressure of 10 lbs. on the steam branch to the stills, whereas they previously worked at 16 to 18 lbs. A substantial increase of mother-liquor has given us a corresponding increase of sulphate made, and the larger sized saturator has proved beneficial both for increase and quality of the sulphate made. The dryer runs free from vibration, and gets its maximum speed of about 900 revs. per minute in thirty to forty seconds from starting, and after a four, minutes run gives a moisture content in the

sulphate of under 2 per cent. The Wilton automatic spent liquor valve works very satisfactorily, and is an improvement on the old seal pot.

A process for making neutral dry sulphate is being proceeded with, and a salt practically neutral is being made.

ECONOMIC STATUS OF THE CANADIAN CHEMIST.

THE Canadian chemist finds himself standing at the dawn of what seems a new era, back of which the dark shades of night cast a pall over all that is past. He finds it hard to foretell what the day may bring, for, professionally, he has had no yesterday, and his stumbling progress during the night has brought little of value for his guidance now that his day has dawned. Lack of opportunity has dwarfed his ambition in some instances; the failure of the people to appreciate his ideas and technical worth has developed a reticence which now often retards his progress. The lack of opportunity has been due, in part at least, to our great wealth of natural resources, for since the first settlers arrived in Canada it has been possible to gain a comfortable livelihood by ordinary industry and without the necessity of much research. Such industries as have grown up have used natural supplies lavishly, and have not been under the necessity of working economically or of finding profitable uses for their byproducts. Profits have been good, and it has been always a simpler matter to waste than to work the materials produced incidentally in the course of the manufacture of their main products.

In all this the chemist has had little place. Progress to him means conservation and development, the unfolding of the bud into the beauty of the flower. But there comes a time in every wasteful nation's life when, be it ever so little, a halt is called in extravagant expenditure; then the chemist has a chance. Thus it is that the older countries of the world have been the leaders in chemical research and scientific progress, and the countries most limited in easily available resources have distinguished themselves among their fellows.

Canada has been no exception among the younger and supposedly progressive nations of the world. Year by year dependence upon the older countries increased: more raw materials were shipped out, and more finished products imported. The war stopped much of our import business, and at first a great wal of distress went up; but that was unproductive of satisfactory conditions, and eventually our people went to work, the virility of the young nation asserted itself and great progress was made.

The chemist emerged. He was given a small job in which he saved the firm money and made things which previously had only been produced in foreign lands. A little of the old-time prestige enjoyed by the chemist returned and the Canadian chemist began to develop confidence in his own ability. He remembered that many prominent in industrial development in the United States and Europe were Canadians, graduates of Canadian universities, who, without honour in their own country, had crossed the border to be acclaimed as leaders. One does not have to go farther back than to the name of Robert Kennedy Duncan, that brilliant scholar and magnetic leader, who fathered industrial research in the United States.

So it was that the wasteful process of war in Europe created conditions in Canada favourable to the initiation of national scientific work. Parliament, in response to the nation's appeal, made a humble beginning by appointing the Honorary Advisory Council for Scientific and Industrial Research. The breadth of vision necessary for much advance has, so far, not been characteristic of our law-makers, and the work of the Council has been impeded. Industrially, Canada has made better progress, and to-day more than ever before, Canadian industries are

seeking the assistance of technically trained men, for experience gained during the stress of war has led them to see that money invested in chemical research is likely to return many times over in increased profits derived from better efficiency in their processes, and the utilisation of products formerly wasted. Better co-operation between science and industry may be looked for, and while the economic status of the chemist at the present moment is not good, the increased number of opportunities, now being provided by the captains of industry, makes his future assured. The Canadian Institute of Chemistry is welding the chemists together in a chain across Canada which will enable them better to cope with difficult questions involving their professional status; and the various other chemical societies, flourishing, reflect the new interest. Canada is a country of optimists, and optimism is the keynote of research and progress. If the foundations of research are well laid there need be little fear regarding the superstructure that capital will rear thereon, and the status of the chemist will no longer be a necessary topic for discussion.-Canadian Chemical Journal, iii., No. 12.

CHEMISTRY AND AGRICULTURE.

THIS journal (Canadian Chemical Journal) cannot be sa d to have suddenly become interested in agriculture as a result of recent elections in the Province of Ontario. Agriculture in general has been one of the fields that has given the chemist in the past very large opportunities, and agricultural chemistry has for years been one large branch of the subject. We would point out, however, to those chemists who have found their work in other fields that the whole of agricultural chemistry does not consist in making analyses of fertilisers. Some of the most complex problems and those most pressing for solution are either directly or indirectly connected with the utilisation of soil, the feeding of animals, and the production of crops and food supplies. Like all other branches of chemistry, there are many side lines and much overlapping with other sciences, but on the whole a sound knowledge of the principles of chemical research are essential before much progress can be made in any line or difficulties overcome. We have developed agricultural schools and experimental farms to a very fair state of efficiency, but it is not unfair to say that the various interests of these organisations has left but little energy for any real attacks on research problems. The perfection of the pure sciences in our agricultural colleges has lost much because they were so closely connected with a student body for the most part interested in what seemed to be more practical things, and also for the reason that no close connection was maintained with universities where more of the academic or research spirit might be imbued. Engineer-ing bas contributed to agriculture, practical farmers have been given better methods, better stock, and a keener ambition to develop the soil possibilities, and, on the whole, progress has been wonderful. Now, in order that it may be sustained, our facilities for the application and spread of general agricultural science must be increased, and above all more attention and more suitably trained Canadian minds should be directed towards the solution of basic problems and the development of the new in agri cultural science. Most of the keenest weapons of attack will more than likely be found to be chemical.-Canadian Chemical Journal, iii., No. 12.

RÖNTGEN SOCIETY.-An Exhibition of Radiographic Prints by Members of the Röntgen Society will be held at the Royal Photographic Society House, 35, Russell Square, London, W.C. 1, from January 6 to February 7. The Exhibition will be open daily (admission free) from II a.m. to 5 p.m., and on the evenings of January 6 and 13 till 9 p.m.

HELIUM PRODUCTION.

Bulletin No. 178 C. of the United States Bureau of Mines gives an interesting account of the war development of plants for helium production-though, probably as a war measure, the name "argon was substituted for helium, and the three experimental plants finally constructed became known as argon plants. It is explained that one of these, the Norton process, is the latest practicable development in liquefying and separating gases. The Linde process (Plant No. 1) depends upon the so-called Joule Thomson effect, obtained by the sudden expansion of a highly compressed gas through a small orifice, or nozzle, and the consequent cooling of the gas; the process being elaborated into a self-intensive or cumulative cycle of heat interchange by causing the cooled gas, on escaping, to circulate around the tube leading the initial gas into the

apparatus.

George Claude, of Paris, conceived the idea of a liquefaction cycle with an expansion engine interpolated. Though the Joule Thomson effect is used in the Claude cycle (Plant No. 2), its value is reduced to a minimum, because the compression of the gas in this system is lowered. The maximum cooling effect is produced by the expansion engine, because the compressed gas, on expanding in the engine cylinder, is made to do work, and thus its temperature is lowered.

In the Norton process (Plant No. 3) three expansion engines are used, liquid is throttled, and the heat interchanger and fractionating still are of new design.

In the Linde system an enormous expenditure of power is demanded to compress the gas in order to obtain the maximum effect of throttling; and this energy is then wasted. The Claude system requires much less compression power; but in this system the energy stored in the compressed gas is also dissipated. In the Norton system the requirement for gas compression is reduced to a minimum by the interpolation of the multiple-expansion engines, and what is needed is conserved and re-applied through the energy developed by these engines. Thus the maximum cooling effect is obtained at a minimum cost.

As the result of experiments made and work done, it is confidently expected that helium of the highest purity will soon be produced by Plant No. 3 on a large scale.-Gas Journal.

NOTIFICATION OF EPITHELIOMATOUS AND CHROME ULCERATION.