CHEMICAL NEWS, ¡ Protection of the Health of Munition Workers. Bromothymolsulphonephthalein is also being studied by Lubs and Clark in the same way as to the effect of protein and salts. It shows a colour change from 6 to 7.25 from yellow to blue. So far as we are informed there is no satisfactory indicator now known covering this range of 6 to 8. Sörensen says of this whole region, "il serait certes désirable de trouver des indicateurs supplémentaires." The colour change in the case of dinitrobenzoylene urea is from colourless to greenish yellow, the colour developing regularly with the change in hydrogen-ion concentration from 6 to 8. This colour change closely resembles that of p-nitrophenol, possesses the same advantage as a one-colour indicator, and the same disadvantage due to its colour being yellow. This is of interest, as the compound is structurally more closely allied to p-nitrophenol than to any of the other indicators cited, since it may also be regarded as of nitrophenol type. It is but slightly affected by neutral salts and not at all by chloroform or toluene. Sörensen found that egg albumen was the most troublesome of all proteins with indicators, but that it did not affect p-nitrophenol. Comparative tests with egg albumen showed that dinitrobenzoylene urea is no more disturbed by it than is p-nitrophenol. The colour of this new indicator fades but slowly. In phosphate solutions it did not fade appreciably in two days, and but very slightly in a week. (The primary and secondary alkaline phosphate solutions used throughout were prepared as described by Sörensen, i.e., were 1/15 molar). 141 NH2 NHCONH, C6H4 C6H4 COOH COOH NH–CO C(OH) C6H4 C6H4 CO-NH C(OH) = N acids, yielding a dinitro derivative whose mono-sodium The benzoylene urea is nitrated with sulphuric and nitric nitro groups has not been definitely determined as yet, although one is quite certainly in position 6. The indicator action may be due solely to keto enolic tautomerism, or the nitro groups also may play a part by pseudo-acid tautomerism themselves. In this connection the second colour change already noted at 11 to 13 is quite possibly due to the ionisation of the second hydrogen. salt is used as the indicator. The location of the two The study of benzoylene urea and related compounds is being continued, and it is hoped that other serviceable indicators will come to light in the prosecution of the work. (To be continued). THE PROTECTION OF THE HEALTH OF WITH SPECIAL REFERENCE TO THE AIMS AND Work of By EDGAR L. COLLIS, M.B., Thus, it would appear preferable to rosolic acid (coralline) for the preparation of neutral ammonium citrate THE lecture provided an outline of the problems of modern solutions for fertiliser or soil analyses, since the hydrogen-industrial hygiene as they have presented themselves to ion concentration of such solutions lies near the middle of the Health of Munition Workers Committee of the its range, and it is possible to make much more accurate Ministry of Munitions. readings with it than with the older indicator. In titrations the acid side of the end point gave an index of 5.93 and the alkaline side 6 09. as measured by electromotive force determinations with the apparatus described by Fales and Nelson (Journ. Am. Chem. Soc., 1915, xxxvii., 2781). These tests were made on phosphate solutions, as the reduction of the indicator by the hydrogen made it impossible to carry out these E.M.F. measurements in its presence, and because a buffer was necessary The to keep the hydrogen-ion concentration constant. figures recorded correspond to a change in hydrogen-ion concentration of 3.6 × 10-7, or less than o'004 cc. of o or molar mono-acid alkali to 100 cc. of solution (assuming ionisation to be complete). In practice the change was obtained with one drop of oor molar NaOH. To give an equally distinct change under similar conditions requires in the case of p-nitrophenol 5-6 drops, and for methyl orange 10-12. Titrations of oor molar HCI checked to within o'r per cent. This indicator can be used in hot or cold solutions, and its colour is unaffected by nitrous acid. It gives a sharp end-point with ammonium hydroxide solutions and hydrochloric acid. It can be used with NaOH and acetic acid, but it is impossible to titrate to the first yellow colour. It cannot be employed to titrate carbonates, but the error due to small amounts of CO2 is negligible. It gives a second colour change at 11 to 13, when the yellow colour becomes much deeper, but this is too alkaline for most practical purposes. An attempt was made to use this colour change for titrations of boric acid with NaOH, but it proved abortive, partly because the indicator gave a pale yellow colour on the acid side of the end-point, but principally because in such a strongly alkaline solution a small change in index requires a large amount of alkali. Dinitrobenzoyleneurea is readily prepared from anthranilic acid by converting the latter first into the uramino (ureido) acid, which then easily condenses to benzoylene urea,- THE WORK OF THE COMMIttee. Simple Laws of Physiology Formulated for Guidance. The Committee realised that, if the health and efficiency of the works were to be maintained, ft could only be accomplished by having regard to simple laws of physiology, such as the following : (1). Alternation of rest and work must be maintained. (3). Suitable light, temperature, fresh air, and protection (4). The physical organisation of a woman, though weaker than that of a man, is more suited to continued effort. (5). Human beings must, during immaturity, have shorter periods of activity and longer periods of rest than are required by adults. The Carrying Out of these Laws. than the exception for work to continue every day of the week. The result was a failure; it being found that the 1. At the beginning of the war it was the rule rather * Abstract of a Lecture delivered in connection with a course o lectures on " Public Health Problems under War and After War Con ditions," at the Royal Institute of Public Health, March 14, 1917. output was no greater than for 'six days, while the effect at. PROCEEDINGS OF SOCIETIES. ROYAL SOCIETY. Ordinary Meeting, March 8, 1917. Sir J. J. THOMSON, O.M., President, in the Chair. PAPERS were read as follows: "Some Effects of Growth promoting Substances (Auximones) on the Growth on Lemna minor in Culture Solutions." By W. B. BOTTOMLEY. 2. At the outbreak of war only a few factories were provided with canteens, but since then, owing to Canteen Committees, there have sprung into existence a large number of industrial canteens. The facilities thus offered 1. Raw peat when further decomposed by means of for obtaining better food have done much to avert the aerobic soil organisms-"bacterised peat"-is found to industrial breakdown so greatly feared, and have proved-contain certain growth-promoting substances (auximones). what we never sufficiently realised before-that, even from the lowest standpoint, the expenditure of money and time in this direction is amply repaid by increased efficiency. 2. Lemna minor plants cannot maintain growth for any length of time in culture solutions containing only mineral nutrients. for complete growth. 4. The addition to the mineral culture solution of 368 parts per million of organic matter from the water extract of bacterised peat resulted, after six weeks, in a multiplication of the number to twenty times, and an increase in 3. Fresh air is as necessary for the preservation of health as food. This simple fact has apparently not been realised by the architects of factories, where, too often, the welfare of the operative has been subordinated to the housing of the machinery, the result being that, owing to overcrowding and want of light and air, infectious com-weight to sixty-two times, that of the control plants. The plaints make havoc among the workers, to the serious detriment of output. Other matters dealing with healthy environment which have received attention from the Com- It 5. The question of juvenile employment presented a serious problem, owing to the risk that the demand for labour would lead to the employment of juveniles for too long intervals at a time when housing and travelling accom modation presented special difficulties which shortened even more the period of rest. Much has been done in regard to welfare supervision, but much more remains to be done if the physique and mentality of the nation are to be preserved and improved. CONCLUSIONS. Many of those problems under consideration, whether concerning the employment of men, women, or children, have only recently been grappled with, and it is amazing that such a stage of industrial progress should have been reached without any serious attempt to solve them. Had the attempt been made earlier much of the bitter heritage of labour unrest which has descended to us might have been spared. We can only hope that, with the new insight which the war has brought us, better understanding may prevail, and the welfare of the industrial population, upon which the prosperity of the Empire depends, be safeguarded to the utmost of our power. water extract free from humic acid, representing an addi- 6. The beneficial effect of the auximones was not due to a neutralisation of the toxic substances present in the ordinary distilled water, since comparable results were obtained with conductivity water. auximones, showed that the plants are very sensitive to 7. An interchange of culture solutions, with and without the presence or absence of these substances. "Some Effects of Growth-promoting Substances (Auximones) on the Soil Organisms concerned in the Nitrogen Cycle." By FLORENCE A. MOCKERIdge. Peat which has been further decomposed by the action of certain aerobic soil organisms under suitable conditions (bacterised peat) contains plant growth-promoting substances (auximones). This investigation deals with the effect of bacterised peat and the various auximone-fractions obtained from it upon the four chief groups of soil bacteria concerned in the nitrogen cycle, in situ and in liquid culture. The addition of bacterised peat to soil increased the rate of nitrogen fixation quite independently of any bacteria contained in the material. This increase was not due to aeration, ncr could it be brought about by chemically treated peat. Experiments in liquid culture showed that a water extract of this material greatly increased the nitroCatalytic Decomposition of Benzoyl Chloride.-gen fixation of Azotobacter and of Bacillus radicicola. An Alph. Mailhe and F. de Godon.-Diphenyl can be con-alcoholic extract and the decomposed phospho-tungstic veniently and easily prepared by the hydrogenation of benzoyl chloride over divided nickel or nickel chloride. Also benzoic anhydride can readily be obtained by the decomposition of benzoyl chloride over barium chloride or thorium oxy-chloride, heated to 420-450.-Bull. Soc. Chim., xxix.-xx., No. 12. acid and silver-baryta fractions from it were also very effective. Similar results could not be obtained with chemically-prepared soluble humus or with artificial humus. The accumulation of nitrate in soil containing bacterised peat was greater than that which could be accounted for by the soluble nitrogen which it contained, and took place more rapidly than in a similar sɔil provided with an equal amount of soluble nitrogen as ammonium sulphate. Since the water extract of the material was found to be directly nitrifiable, its effect upon the rate of nitrification was not tested, but the auximone-fractions, which were not nitrifiable, greatly increased the rate of nitrification of ammonium sulphate solutions. The auximone fractions were without effect upon the rate of ammonification in soils and upon the ammoniacal fermentation of urea. The water extract had no effect upon the rate of denitri fication, but the auximone-fractions directly inhibited the process. The work indicates that certain decomposition products of organic matter stimulate the activities of certain soil bacteria, and appear to play an important part in nitrogen metabolism. 3 PHYSICAL SOCIETY. Ordinary Meeting, March 9, 1917. Prof. C. V. Boys, F.R.S., President, in the Chair. A PAPER entitled "To Measure the Pressure in a High Vacuum by Observations of Logarithmic Decrement." By Dr. P. E. SHAW, BA, D.Sc., was taken as read in the absence of the author. In experiments on the Newtonian Constant (Phil. Trans., May. 1916) the author used a torsion balance in a vacuum which varied in different cases from 15 mm. to 0'0000 mm. pressure. Before sealing the vessel the pressure was determined by a McLeod gauge. Values of the pressure after sealing off were deduced, in the case of the higher vacua, from observations of the damping of the torsion system. The formula employed is due to the late Prof. Poynting, and can be expressed in the form A paper on "A Diffraction Colour Box" was read by Mr. A. W. CLAYDEN, M.A. The apparatus consists essentially of a very simple concave grating spectroscope, of which the slit and grating are situated at opposite diameters of a circle, the spectrum being formed on the arc of this circle. Two independent arms carry fittings on which may be placed either telescope eyepieces or small electric lamps. With the slit of the instrument illuminated by a suitable source, the eyepieces can be set so that any two desired wave-lengths are in the centres of their respective fields of view. The eyepieces are then replaced by the small lamps (the filaments coinciding with the previous positions of the crosslines), and the grating is observed with a small telescope pointed towards the widened slit: the whole of its surface is seen to be illuminated with a mixture of the two colours on which the eyepieces were originally set. The "concave grating" employed consists of a Thorpe replica of a Rowland plane grating of 14,475 lines to the inch, mounted with its ruled surface in contact with the surface of a concave mirror of 4 ft. focal length. This forms an admirable substitute for the more expensive concave grating. The author prefers to state results in terms of the number of oscillations per unit of time. Observations showed that the smallest change of wavelength which could be recognised by the eye as a change of colour was greater than that which corresponded to a | 143 change of period of 1012 vibrations per second, or to a change of one vibration more or less in 1/1012 second. DISCUSSION. Mr. TROTTER asked how the minimum difference of wave-length detectable as colour difference compared with the values obtained by Dr. Edridg. Green. Mr. T. SMITH said that experiments on the minimum colour difference which the eye could detect were valueless unless the exact conditions under which the experiments were made were stated. For example, the comparison of two colours side by side is materially affected by the presence of a black space between them. In Dr. EdridgeGreen's experiments the conditions were not good. The experiments were made somewhat as follows:-While viewing the extreme red end of the spectrum, a shutter is brought down towards the red so as to cut off everything above the region to which the observer would give one distinguishing name, such as deep red. A second shutter was then brought up from the red end to cut off the first patch, and the first shutter moved along the spectrum until the boundary of the next "monochromatic" patch was located. By this means the whole spectrum was divided up into about 25 mono-chromatic patches. It is not difficult to repeat these observations, but if they are compared with measurements made in another way entirely different results are obtained. Lord Rayleigh was able, for instance, to distinguish between the colour of the two sodium lines. He had two spectra, one above the other, the upper one being inverted, so that D, and D2 of one spectrum coincided with D2 and D. of the other. | Colour comparisons should always be made from simultaneous observations of the two colours. Prof. C. V. Boys said he would like to emphasise Mr. Smith's remarks about the effect of varying conditions on the visual estimates of colour. In the colours of soap films, for instance, this difficulty is met with. Where the thickness is nearly zero the colour is black. As the thickness increases the colours of the first order are successively encountered. Between the blue and yellow there is a tint which can only be described as a bad white. He had long been puzzled as to what this colour was, but had eventually discovered a method of overcoming the deceptive influence of the adjacent colours. Usually these films are traversed by long thin folds. The thickness of the folded film is everywhere three times that of the adjacent unfolded film. Points can be found where this doubtful region between the blue and yellow, occurring on the triple film, can be directly contrasted with the first order white in the adjacent single film. It is then seen to be a very good green. A point which had surprised him in connection with Mr. Clayden's apparatus was that the plane grating, which could not be in actual contact with the mirror except at its edges, nevertheless behaved as if it were in good optical contact. Dr. W. ECCLES pointed out that the minimum colour difference estimated by Mr. Clayden to be perceptible to the eye, if expressed in the same way as an interval in music, works out as about 10013. The tone difference just perceptible to the trained musical ear has been stated to be one seven-hundredth of an octave, which works out as 1'001. It is interesting to observe that the sensitiveness of the eye to pitch differences is, like its sensitiveness to inflow of energy, of the same order as that of the ear. Mr. CLAYDEN, in reply, said that in making his experiments on the minimum difference of wave-length required to produce a noticeable change of colour he had arranged matters so that by using a reversing or non-reversing eyepiece in the observing telescope one or other colour was uppermost in the field of view. The difference in wavelength was then reduced until it was impossible to say which was which. By this method he could detect a difference of two vibrations per 1/1012 sec., but at the red and violet ends of the spectrum the detectable difference greatly increased. With regard to the President's last remarks, he had himself been very agreeably surprised to find that the performance of the grating was so satisfactory. An arrangement for showing by projection on a screen the coloured fringes exhibited when a Thorpe grating is laid with its ruled face against a plane mirror was shown by Mr. A. W. Clayden. The light from a small lantern is incident in an approximately parallel beam on the interface of the grating and mirror, which are held together in a wooden framework supported on a stand. The position of the grating mirror combination is adjusted so that the central reflected beam or any one of the diffracted beams is returned just alongside the lantern. The beam passes through a projection lens which focuses the fringes on a distant screen. The fringes thus obtained are very bright, and the simplest apparatus and adjustments suffice for their production. DISCUSSION. Dr. R. S. WILLOWS mentioned that Fellows had in formed him that these fringes had been described by Barus in the Philosophical Magazine (July, 1910, and July, 1911). He understood that they had also been exhibited by Rheinberg at the Optical Convention in 1910. Mr. Clayden's method of exhibiting them by projection would, he thought, be distinctly us:ful to teachers. An apparatus for studying the effect of Hertzian Waves on the Heart was exhibited by Prof. W. M. COLEMAN. The above analysis of the salt obtained in this way repre sents the sodium present regarded as present in an amount comparable with the errors of experiment, and the water, regarded as water of crystallisation, 24H2O; the alumina and ferric oxide being isomorphically interchange. able. The SO, estimation alone in this experiment would give the formula of the salt as required. A further experiment for the amount of Fe2O3 gave the Fe2O3 calculable to the above salt as FeO3, also wi hin the er.or of experi ment, as giving the formula of a salt, 5Fc203Na2O.4SO3, possible.-J. C. THOMLINSON. B Sc. MEETINGS FOR THE WEEK. TUESDAY, 27th.-Royal Institution, 3. "Geological War Problems," by Prof. J. W. Gregory. A simple pendulum, consisting of a cylindrical brass bob terminating in a pointed wire coaxial with the bob, bangs by a piece of string above one of the terminals of an induction coil, so that in its lowest position the point of the bob is within sparking distance of the terminal and vertically above it. The bob is connected by a piece of THURSDAY, flexible wire to the other terminal of the coil. When the pendulum is set oscillating there is a shower of sparks every time the bob passes its lowest position. The frequency of intermittence can be varied by altering the length of the suspension. By adjusting the period of the pendulum nearly to the time of a heart-beat any possible effect on the rate of the beating may be observed. The condensed discharge from two Leyden jars is employed. CORRESPONDENCE. INDUSTRIAL HOLIDAYS. To the Editor of the Chemical News. SIR,-I enclose a copy of a letter which has been sent to all Trades Unions, Employers Associations, and the members of both Houses of Parliament, Lord Mayors, and Mayors. Those who are interested in the question will be very glad if you can see your way to give it publicity in your columns. SIR,-The incidence of public holidays, though hallowed by custom, is uneconomic and inconvenient both to manufacturers and workpeople. It is now suggested that the Whitsuntide holiday should be dispensed with, and that in its place a full week's holiday during the summer or autumn months should be substituted. If this suggestion were adopted, it might be found desirable to divide the country up into trade areas—say, twelve in number-and to arrange for the areas to take their holidays in successive weeks. The advantage of this plan-from the point of view of those who cater for holiday. makers-would be obvious, as it would give them a steady trade spread over a quarter of the year, instead of a glut of business at intervals. I should be very grateful if you would be so kind as to let me have your opinions and criticisms of this proposal as soon as possible.-I am, &c., PERCY CREED. FRIDAY, 30th SATURDAY, Royal Society of Arts, 4.30. "Land Settlement in 22nd.-Royal Institution, 3. "Modern Improvements in Royal Institution, 5.30. "Recent Developments of THE MERSEY CHEMICAL WORKS, Ltd., BROMBOROUGH PORT, NEW FERRY, BIRKENHEAD. To CHEMICAL MANUFACTURERS, DYERS, ENGINEERS, and OTHERS. WHEATLEY KIRK, PRICE, and CO. are instructed by the Board of Trade to offer for SALE by PUBLIC AUCTION, in ONE LOT, at the LAW ASSOCIATION ROOMS, COOK STREET. LIVERPOOL, on WEDNESDAY, MARCH 28th, 1917, at Three o'clock p m. prompt, the whole of the MODERN and EXTENSIVE FREEHOLD PREMISES, PLANT. and STOCK of the above-named Company. The LAND is FREEHOLD, and occupies an area of 361 acres or thereabouts. The BUILDINGS are modern, substantially built, lofty, and welllighted brick-built structures, comprising Offices and Laboratory; Power and Boilkr House, Fitting Shop, &c.; Hydrosulphite Factory; Colour Factory; Mixing Room Warehouse; Gas Plant Shed; Time Office; Mess Room. Residue Shed; Store Sheds; Weigh House; Cycle Shed: Boundary Walls, Fences, &c., &c. The PLANT and MACHINERY is modern, in excellent condition, and comprisesRivetted steam-jacketted Boiling Pans, Montejus, Mixing Pans. Filter Tanks, Receivers, Condensers, Pumps, Vacuum Ovens, Hydraulic Presses, Fume Chambers, Electric Hoists, Storage Tanks, Stills, Weighbridge, Weighing Machines, Lifting Beams, &c., &c.; complete Fitting Shop Tools and Appliances. The whole of the ELECTRIC LIGHT AND POWER INSTALLATION; LOOSE TOOLS; STEAM, WATER, GAS, FIRE, HYDRAULIC, COMPRESSED FIXTURES; TRAMWAYS, WAGONS, BOGIES, &c.; together with theAIR, TELEPHONE, and VACUUM SERVICES; OFFICE FURNITURE ; STOCK, STORES, and WORK-IN-PROGRESS. Plans and Particulars may be obtained from the AUCTIONEERS 16, Albert Square, Manchester; 46, Watling Street, London, E.C.: and 26, Collingwood Street, Newcastle on-Tyne; from Messrs. Street, Liverpool; or from Mr. W. E. MOUNSEY, F.C.A., of BATESONS, WARR, and WIMSHURST, Solicitors, 14, Castle Messrs. Lewis and MOUNSEY, Chartered Accountants, 3, Lord Street, Liverpool, to whom applications must be made to view the Works. CHEMICAL NEWS 1 Advertisements. WAR NOTICE Issued by an all-British Firm employing all-British labour, whose capital is and always has F. E. BECKER & CO., 17-27, HATTON WALL, W. & J GEORGE (London), Ltd., Proprietors. BACK NUMBERS AND WE have E.C. 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