July 2, 1920 island and accounts of the more recent deposits are given as long as present conditions last, not a serious rival, | each formation. The history of the glaciation of the neither is she able to pay what she owes as reparation. THE TREND OF TRADE.-In these days of preoccupa tion with many things-the procession of wages claims, the sporadic strikes and rumours of strikes, the threat of capital levies, the difficulties of production, the scarcity of money, and the prospect, both welcome and unwelcome, of a break in prices-it is useful to watch the Board of Trade returns. They are an index, though not, perhaps, a complete one, to the main course of events. And for the last few months they have been consistently encouraging. Those for the month of May show an adverse trade balance of 35 millions, which is the lowest figure for any month since the Armistice. Exports reached the record figure of 119 millions, an increase of 85'4 per cent over the corresponding month of 1919, and of 12.3 per cent over the April, 1920, figure. The imports were 116 millions, showing a percentage increase of 22.6 over the 1919 figure. Re-exports totalled 20 millions, an increase of 76.2 per cent. To some extent, of course, these increases are due to higher prices, but the main thing is the fall in the adverse balance of trade from 40 millions in April last and 59 millions in May, 1919. Comparing the past month with May, 1919, the exports of iron and steel rose from £5.384.215 to £11,958,241, and of machinery and mill work from £2,502,610 to £4,851,193. Electrical plant, chemicals, oils and fats, and, indeed, all other manufactures, share in the increased activity. The advance indicated by these figures is encouraging, but it is still more valuable as an index to the rapidity with which the country would reach a really sound industrial condition if all ranks were united in augmenting production, and if the problem of national expenditure were tackled in a more drastic manner than seems to be within the power or the will of the present Government. REVISION OF THE SERIES IN THS SPECTRUM OF BARIUM.-F. A. Saunders (Astrophysical Journal, January, 1920.)-The spectrum of barium contains three systems of series, the triplets, the single lines, and the pairs. After making a careful study of all available data, including recent unpublished observations by King, the author has revised and extended the previously recognised series of triplets and single lines and has identified the lines corresponding to one or more terms of each of several other series. Altogether about 135 lines are assigned to one or other of sixteen series, which include four series of triplets, two triplet combination series; four series of single lines from single-line combination series, and two inter-system combination series. Accurate con: stants for these series are given. The fundamental and diffuse series of triplets are unusually complex, and these and other series show curious irregularities both in the relative intensities of the terms and in the wave-lengths. No simple formula of the ordinary type will give the frequencies accurately. The paper includes a brief explan ation of the notation used in designating the different series. GEOLOGY OF ANGLESEY.-The Minister of Agriculture and Fisheries desires to draw attention to the publication, by the Director of the Geological Survey of England and Wales, of a Memoir on the Geology of Anglesey; containing 980-xl pp., and illustrated by 347 figures, 61 photo graphic plates, and 17 folding plates (4 being coloured). Two volumes, cloth 8vo. By Edward Greenly. Price £3 38. net. The description of the crystalline schists, and of the various gneissic, volcanic, and sedimentary rocks which are included in the complex, occupies Parts I. and II. of the book. The structures of these rocks are dis. cussed, and the stratigraphical order in which they may have originally been formed is suggested. Part III. deals with Cambrian, Ordovician, Silurian rocks, the Old Red Sandstone, and the Carboniferous group in which are in cluded the Coal Measures. The various igneous rocks intruded into them during Paleozoic and Tertiary times are described, and a full discussion given of the fossils of ARE PROFITS NECESSARY ?—The very mention of profits in some quarters nowadays is as efficacious, metaphorically speaking, of producing a human tornado equally as the waving a red flag in front of a bull is likely to be productive of remarkable evolutions on the part of that animal. The other spheres, where profiteering perhaps is the sole element of consideration, the question of what constitutes profit creates perplexing thoughts, and again, in higher circles, the manifold problems associated with profits and profit-making are exercising the minds of our most advanced thinkers. In point of fact, it is a topic of debate in all countries, a topic which all seem to realise the importance of, yet opinions on many issues involved seem as divergent and wide apart as are the poles. It makes one wonder whether a point on which commonalty of interests can mature will ever evolve. In this month's issue of the Industrial League and Council Journal is an "Are Profits Necessary?" contributed by article on Mr. E. J. P. Benn, C.B. E., in which the writer illustrates clear lines of demarcation. "It makes my blood boil," he says, "when I see some Polish Jew land on these shores and, within the space of a dozen or twenty years, become a millionaire. There is something wrong with a system which will keep a highly educated man of science working all his life in comparative poverty and allow an illiterate, vulgar, fat cosmopolitan financier to amass wealth to his heart's content. The capitalistic system, the profits system, will not, in my judgment, stand examin ation from the ethical or Utopian point of view. Morals should exercise an influence over industry, as, indeed, they should influence all our actions. But to substitute morals for actions themselves does not, unfortunately, work out as we should like it to. It does not give us houses; it does not reduce prices; it does not increase supplies and it does not add to our material comfort. Industry, to me, is something which is concerned with the feeding and clothing and housing of my wife and children; moral is, on the other band, something which enables me and them to lead a better life. The two things are inex. plicably mixed up together, but they are not, and never will be, substitutes one for the other. Taxation of all kinds does not, as is commonly supposed, reduce the rate of profits; it merely turns the profit-maker into a taxcollector, and he, very naturally, charges another profit for collecting the taxes. But the commonest fallacy is that you can reduce profits by increasing wages, or that wages come out of profits, or profits out of wages. Nothing of the kind is, in fact, true. I therefore come to the conclusion that, in the present state of development of the human race, there is no more chance for platonic industry than there is for platonic love, and I do not want to see civilisation destroyed and the human race reduced to savagery and starvation by the chasing of an ideal which may apply to angels, but cannot apply to mere mortals. If instead of endeavouring to exterminate the profiteer we were to encourage him, there would be so much competition among profit makers as to reduce profits to an economic level. That is the business-like thing to do." Many other interesting articles, including those on the subject of "Profit Sharing" and "Economical Production and Prevention of Waste," are contained in the Industrial League and Council Journal, copies of which can be obtained from any station bookstall. Senior Assistant wanted in Iron and Steel Works Laboratory. State age, experience, and salary required.-Address, The Secretary, Consett Iron Co., Consett, county Durham. ASSISTANT CHEMISTS wanted at once for the Admiralty Inspection Laboratories at Holton Heath. Candidates must have a qualification equivalent to that of the Associateship of the Institute of Chemistry, and must possess a sound knowledge of Technical Analysis, preferably explosives. July 2, 1920 The posts are non-pesionable and the salary is subject to bonus, and Editorial Offices at 16, Newcastle the present value of the commencing salary being £319, risi. g by £16 annually 10 £412. Applications, stating qualifications and experience, should be made by letter to the INSPECTOR OF NAVAL ORDNANCE, Holton Heath, near Wareham, Dorset. Wanted, Assistant Chemist experienced in Iron, Ste-1, and Ferro-alloy Analyses. Salary £300 to £350, according to qualificat ons and experience.-Address, Box 782, Scott and Son, 63, Ludgate Hill, London, E.C. 4. Street will be closed for the purpose of removing to 97, SHOE LANE, LONDON, E.C. 4, which will be opened for business at Wanted, well-trained LABORATORY AND 10 a.m. on Monday, July 12. LECTURE ROOM ASSISTANT to take charge in the Chemical Department, McG 11 University, Montreal, Canada. Duties: Distribution and ordering of Supplies and Apparatus, setting up Lecture Appara us, simple Repairs, &c. Must be experienced, steady, and have mechanical ability. Wages 30 dollars per week. Duties begin September1 5.-Apply, with reterences and qualifications, to G. S. WHITBY, 8, Victoria Avenue, Hull, Yorkshire, b fore August 10. KIESELGUHR (Diatomite). All grades for ell purposes always in stock at principal ports.-A. Eggermont, 127, Albert Road, Middlesbrough. PERIODICALS wanted to PURCHASE. JOURNAL CHEMICAL INDUSTRY, 1914-191; JOURNAL OF CHEMICAL SOCIETY, 19 4.919 and 1871-1874.Priced offers to W. MULLER, 26, Hart Street, W.C. 1. NORTHERN POLYTECHNIC INSTITUTE HOLLOWAY, LONDON, N. 7. UNIVERSITY OF MANCHESTER. DEPARTMENT OF CHEMISTRY. Applications are invited to fill the following the Chemical S aff: (1) A READER or SENIOR LECTURER IN ORGANIC CHEMISTRY, or, alternatively, LECTURER IN ORGANIC CHEMISTRY. (2) A LECTURER IN INORGANIC AND PHYSICAL CHEMISTRY. (3) Three ASSISTANT LECTURERS IN CHEMISTRY. Applications should be forwarded, not later than JULY 15 next. to the REGISTRAR, from whom detailed conditions may be obtained. MICA. Telephone The he Governors of the above Institute invite F. WIGGINS & SCNS 102/3/4 Minories, London, E applications for the Post of ASSISTANT CHEMICAL LECTURER. Must have good Honours Degree. salary £50 per annum. Commencing Particulars and forms of application to be obtained from the Clerk to the Governors. BIRMINGHAM MUNICIPAL TECHNICAL Principal-W. E. SUMPNER, D.Sc. Applications are invited for the HEADSHIP OF THE CHEMICAL DEPARTMENT, now vacant by the appointment of Dr. T. S. PRICE as Director of Research to the British Photographic Research Association. Full particulars of the appointment can be obtained from the SECRETARY, Municipal Technical School, Suffolk Street. Birmingham. MICA MERCHANTS, THE CHEMICAL NEWS. publication. VOL. CXXI., No. 3143. EDITORIAL. WITH a view to increasing the usefulness of the CHEMICAL NEWS, it has been decided to introduce in the near future a new feature in the method of It was the aim of the late Sir William Crookes, that the CHEMICAL NEWS should be the medium for the publication of original thought among Chemists and Physicists, and in its columns most of the discoveries of the past fifty years have appeared; in some cases the CHEMICAL NEWS was the first organ of publication. The present Editor desires that the Journal shall maintain its useful character, and is anxious to meet as far as possible the many suggestions that have been made to this end. Recently numerous original communications have been received, but lack of space and difficulties in printing have caused delay in publication; these difficulties are likely to increase rather than diminish. It has therefore been decided to arrange a weekly "Editorial Notice", to announce, and if possible give a brief summary of, any papers received during the week, but of which, for the reasons stated, publication may have to be deferred. The Editor therefore suggests to authors that a short summary should accompany original communications, so that an announcement can appear immediately. Such announcements must be very brief, and should at most occupy but a few lines, giving only such details as are necessary for immediate publication. The Editor would be grateful for any further suggestions that would help to make the CHEMICAL NEWS of greater value to the profession generally and to maintain its character as a means of publication of original thought in Chemistry and Physics. SUBSTANCES DISSOLVED IN RAIN AND SNOW. DURING the period from 1908 to 1917, F. T. Schutt and R. L. Dorrance, of Ottawa, Canada, conducted a series of analyses of rains and snows that fell in that section of the country. In 1914, under the direction of Dr. N. Knight, of Cornell College, a similar set of investigations was begun with the rains and snows that fell at the town of Mt. Vernon, Iowa. Mt. Vernon is a town of about 2,500 population and has no manufacturing of any kind, the nearest industrial centre being some 17 miles away. With this in view, the rains should be remarkably free from contamination from city smoke and gases. The samples of water were gathered in two porcelain pans near the centre of the town, and every precaution was taken to prevent contamination of any sort before analyses were made. The rains were analysed as soon as possible after precipitation. This work is a continuation of that done by J. E. Trieschmann, published in CHEMICAL NEWS, Aug. Ist, 1919. 22nd, 1920, there was a total rainfall of 11:37 inches During the year from October 9, 1919, to May and a total snowfall equivalent to 2:07 inches of rain. During this period there were 21 precipitations of rain and 8 of snow. The total rain and snow as rain was 13:44 inches. The largest rainfall occurred on October 9-10th, when there fell 2.6 inches. The appearance of sulphates in rain is ascribed to the sulphur in the smoke of the atmosphere. Mt. Vernon being only 17 miles from a manufacturing city, it is very probable that the presence of sulphates is due to smoke from this neighbourpounds of sulphate as SO, fell per acre. ing city. During this period, the sum of 510306 The largest amount at any one time fell on March 4, which amounted to 34 parts per million of water, or 7.7137 pounds per acre. A total amount of chlorine equal to 48.1644 pounds per acre fell during this time. This is equivalent to 79 36 pounds of sodium chloride. The presence of chlorine in rain is said by Dr. N. Knight to be due to minute particles of NaCl carried by air currents from the Atlantic Ocean. The largest concentration of chlorine appeared on December 2, when a light snow equivalent to 0.08 inches of rain fell. At this time, chlorine to the amount of 177 parts per million, or 40157 pounds per acre, fell. Notice is made of the fact that during the showers and periods of small rainfall, the greatest concentration of chlorine occurred. No particular reason can be given for this occurrence. nitrates (NO,), as nitrites (NO,), as free ammonia, Nitrogen was determined in four forms: As and as albuminoid ammonia. Nitrogen in the forms of nitrites and nitrates is probably caused by its oxidation during electric discharges in the atmosphere. A total amount of 0.62841 pounds of nitrogen as nitrate fell, the greatest amount, 0.3 parts per million, or o'06806 pounds per acre, occurring on December 2 and on January 23, at which times snow equivalent to o'08 inches and 0.50 inches fell respectively. As nitrite there was a total amount of 0.03725 pounds per acre nitrogen, the greatest amount coming on March 19, equal to o'02 parts per million of water, or 000453 pounds per acre. At this time 04 inches of rain fell. The presence of ammonia is in all probability due to the action of soil bacteria in the process of the fixation of nitrogen. Free ammonia equivalent to 2.8642 pounds of nitrogen fell in this period. The amount is very large in comparison with nitrogen as nitrate or nitrite. On March 4, nitrogen as ammonia equal to 2:30 parts per million, or 0.52181 pounds per acre, fell with 04 inches rain. Albuminoid ammonia was less frequent in its occurrence, for 32 per cent of the rainfalls gave no tests for it. A total of 0.4974 pounds of nitro gen as ammonia in the albuminoid form fell, the greatest single amount coming on February 12, when 112 parts nitrogen per million, or 0.2541 pounds per acre, fell with snow, equal to 0.25 inches of rain. The total amount of nitrogen as free and albuminoid ammonias was 3.3616 pounds per acre. The total amount of nitrogen as nitrates, nitrites, and ammonias was 4:02726 pounds per acre. Of the total nitrogen, 82.5 per cent was in the form of ammonias. More nitrogen occurred in free ammonia than in any of the other nitrogen compounds. This work was carried on under the supervision of Dr. Knight, and grateful acknowledgment is made of his advice in connection with it. Cornell College, Mount Vernon, Iowa, THE COMMERCIAL APPLICATION OF ELECTRICAL OSMOSIS.* By JOHN SOmerville highfield, M.Inst.C.E., M.I.E.E.; W. R. ORMANDY, D.Sc.; and D. NORTHALL-LAURIE, F.I.C. The THE study of matter in the colloidal state is one of the first importance and is of surpassing interest. The problems resolve themselves into the scheming of methods of studying the rate of movement and the causes of movement of particles of very small size often approaching molecular dimensions. The forces causing movement are molecular, chemical, and electrical, added to the force of gravitation, and the movements may take place in any medium, but usually in water. importance of the subject is apparent when it is realised that many of the largest trades and manufactures depend on the use and proper treatment of matter in the colloidal state. Agriculture depends on a suitable colloidal state of the soil, tanning of leather on the introduction into the cells of matter in colloidal form. The glue and gelatin industry deals with colloidal matter. The dyeing of fabrics consists largely in introducing finely divided material into fibrous matter. Again, by a scientific study of their slimes the efficiency of the recovery of metals can be increased. Papermakers deal with matter in a colloidal state. Trades so diverse as dairy production and paint manufacture are equally concerned in the treatment of colloidal matter. The terms colloid or matter in a colloidal state, true solution and suspension, are not easy of simple definition. For the purpose of the immediate subject, matter in a colloidal state or a colloid means matter in so fine a state of division that it tends, under favourable circumstances, where coalescence does not readily take place, to remain for some hours in suspension. The term Osmosis, or Osmose, appears to have been first used by Graham about 1854; it may have been derived from the Greek word Osmos, meaning "pushing," and the terms Exosmosis and Endosmosis, used by Dutrochet about 1800, refer to a pushing outwards or inwards, osmosis being a general pushing such as the diffusion of liquids through a diaphragm. The importance of the phenomenon has long been recognised, as it is *A Paper read before the Royal Society of Arts, May 19, 1920. one consistently occurring in living bodies, both animal and vegetable. The first record appears to be by Nollet (1700-1770) as a result of experiments with water and alcohol through a bladder. Dutrochet investigated the subject, and his work resulted in numerous applications in methods of dialysis by Graham. Graham insisted that the phenomenon was molecular, and that it is due to the raising of sap in trees against gravity. Graham, in 1861, found that when a weak solution of sodium silicate was poured into excess of hydrochloric acid no precipitate was formed, whereas, if the sodium silicate solution was strong, a gelatinous precipitate of silica was obtained. He found that by placing this clear solution in a small dish made of parchment, and floating it in water, the sodium chloride produced by the reaction passed through the pores of the parchment paper, and, by frequent changes of the surrounding water, could be completely removed, leaving inside the dish the silicic acid, thus proving that it was not an ordinary solution. Graham called the silicic acid when in this condition a Colloid, whereas he termed the salts and other similar bodies that passed through parchment Crystalloids, and the separation of one from another Dialysis. These original definitions have been extended and amplified. A colloidal solution is termed a Sol, and, if water is the liquid in which it is contained, the sol is known as a Hydrosol; if alcohol, an Alcosol, or generally an Organsol if the medium is some organic liquid. The colloidal substance is termed the Disperse Phase, whereas the medium in which it is dispersed is termed the Disperse Medium. Most materials, including metals, sulphides, oxides and salts can exist in the colloidal state. Natural substances occurring in very small particles such as ball-clay, china-clay, and the various types of fire-clay, can be brought into the colloidal condition by suitable means, and most naturally occurring compounds, as emery, quartz, or steatite, and the artificial abrasives, carborundum and alundum, can be rendered colloidal by sufficiently fine grinding. The existence of a material present in the colloidal state in a so-called solution can be demonstrated in various ways. For instance, when the colloidal particles are extremely minute their presence as particles can be shown either by dropping upon filter paper, when the colloidal matter will remain as a stain in the centre, the disperse medium, in this case water, spreading out around it; or by passing a powerful beam of light through the liquid, when the particles will cause the path of the beam to become visible, and the light reflected from the particles to be polarised. This experiment was first shown by Tyndall, and is known as the Tyndall effect. Electrical Properties of Colloidal Solutions.— Picton and Linden found that matter in colloidal suspension, when subjected to direct current of upwards of sixty volts between platinum electrodes, tended after a time to collect either around the anode or cathode, leaving a clear space around the cathode or anode respectively. They investigated this phenomenon and found it to be of general occurrence. It is known as Electrical Osmose or Cataphoresis, and the polarity of the particles depends not only upon the constitution of the particles but on the nature and quantity of electrolytes present, and also upon the composition of the disperse medium in which they are suspended as the disperse phase. Thus, silicic acid is charged positively when in water, and negatively when in turpentine. Generally, the continual suspension of a colloid in the disperse medium is possible only when the colloidal particle retains an electrical charge. The particles possessing the charges of the same sign, either positive or negative, repel each other, and so cannot coalesce or coagulate together. They can be made to coalesce by subjecting them to an electric field by means of immersed electrodes, when they are attracted to the pole of sign opposite to their charge, and are so discharged; this is the industrial method used in the purification of clay. They can be made to coalesce by adding to the liquid an equal number of colloidal particles of opposite charge, when the two sets of particles mutually discharge one another. As an example, the addition to a colloidal suspension of arsenic sulphide of a colloidal suspension of a basic material, such as ferric hydrate, causes the precipitation of the two colloids. The quantity of one colloid required completely to precipitate another colloid of opposite charge varies with the composition of the precipitating colloid. Biltz gives the following figures: 14 m.g. of gold is completely precipitated by :4 mgrms. of cerium oxide; 3 mgrms. of ferric oxide; 25 mgrms. of thorium oxide; 1-6 mgrms, of zirconium oxide; 03 mgrms. of chromic oxide; 01 to 0.2 mgrms, of alumina. The order of power of precipitation varies with the substance to be precipitated, and depends probably upon the absorption capacity of the material. If Another method of bringing about the coagulation of peptised particles is to add to the suspension of a small quantity of a salt which in solution is subject to electrolytic dissociation. the petised particles carry an electro-negative charge, then the added electrolyte must be electropositive; thus, bodies which are peptised by an alkali are precipitated by an acid. The deposition of the fine silt and mud carried down by rivers when the stream encounters the salt of the sea is, no doubt, due to the flocculation of the dispersed particles by the salt electrolyte. In order that the phenomenon of electrical osmose can be shown, it is necessary first that the colloidal material in suspension should be broken up by giving each minute particle an electrical charge, thus preventing coalescence, that is to say the suspension should be peptised. Various materials can be peptised, each requiring different peptising agents: thus, gelatin is peptised by hot and not by cold water; gums by cold water; mastics in alcohol by large quantities of water; metals by fused metallic salts; hydrous oxides by caustic alkali. The special application of these principles, to which we wish particularly to refer, is the purification of clay and similar materials. The commercial application of these phenomena to the purification of the clay is due to the late Count Schwerin. He showed that the addition of small traces of alkali to a suspension of clay in water resulted in the suspension becoming highly mobile, the clay particles remaining for a long time in suspension, the pyrites, mica, free silica, and other impurities which are not peptised, tending to fall through the suspension, Count Schwerin, in his patent specification, points out that bodies in suspension which tend to move to the cathode, require an electrolyte of an acid character to be employed to bring about dispension or peptisation, but that bodies which tend to move to the anode require electrolytes of an alkaline character. It is further of interest, to note that the original inventor not only shows that the addition of suitable electrolytes can be used to peptise the main matter in suspension, to bring about increased fluidity with the object of allowing foreign matter to separate out by subsidence, but he also points out that if one substance is present in varying degrees of fineness, it is possible by the utilisation of the same principles to bring about a separation of the fine particles from the coarse ones. Coalescence of the peptised particles in a clay slip can be produced by discharging the particles by the addition of acid to the suspension; the clay then settles in a gummy flocculated mass, carrying with it the fine impurities as previously explained. The action of the acid and alkali on the slip can be illustrated by reversing the method and allowing a thin stream of neutral clay slip to flow into a vessel containing on the one hand acid, and on the other alkali; in the first, the clay particles fall in a continuous solid stream and settle quickly; in the second, the clay particles spread out broadly and settle very slowly. There are many disadvantages to the floccula tion of the clay by coagulating with electrolytes; certain fine impurities remain in suspension and are carried down with the flocculated clay, so that only partial purification is attained. The physical state of the clay is entirely altered, and the clay is left in a form difficult to collect and dry. For these reasons, the electrical method of purification was developed. If, in the prepared suspension, two electrodes are immersed, and a difference of electrical potential be established between them, the clay particles move to the anode, where they discharge themselves and adhere as a coagulated mass, and the water is driven to the cathode, leaving the clay in a semi-dry state attached to the anode. The fine particles of silica, mica, pyrites, and other impurities, either migrate to the cathode or are washed away by the water stream moving to the cathode. This is an example of using direct electrical pressure to produce coalescence in a peptised suspension. The effect of the practical application of the process on clay is to remove particles of mica, silica, pyrites, and felspar, and to leave the clay substance in a satisfactory state for final drying. (The effectiveness of the purification was illustrated by reference to photo-micrographs). It is, perhaps, allowable at this stage to indicate some of the directions in which the osmotic treatment of clay leads to advantages, having a direct and practical bearing upon industry. It is not realised sufficiently that the melting-point of pure |