NEWS

two.

"The reader may recall the process of blue-smoking employed in the manufacture of black roofing tiles and brick and described in an account of the Belgian clayworking industry. A similar process is again met in English brickmaking, save that the effect of the dark colour is enhanced by a kind of glaze possessing a matt lustre, not to be confounded with the appearance of our glossy lead glazes.

"The process for the prodution of the brick in question, styled 'blue Staffordshire bricks,' or 'iron bricks,' from their appearance and hardness, has its home in the centre of the Staffordshire potteries, and in the south, in Bishops Waltham, not far from Southampton. The clay used is a ferruginous but rather refractory clay; the bricks produced from it approach in appearance closest those known in the Berlin market as Rathenow bricks, or those that are made from a clay originating from the weathering of the red carboniferous sandstone in the Saarbrücken coal basin. The clay for the brick is generally well prepared, usually by slumming. To produce a denser and more finished surface the better grades of brick are always re-pressed. Burning is carried on to vitrification either in the ordinary Staffordshire kilns previously described or in smaller ones similar to them, of round shape about 3.5 metres in diameter and 2'5 metres high, arched over, and fitted with six fire boxes distributed round the circumference, and four to six small chimneys set on the semicircular crown for the exit of fire-gases. The bricks are set in them in such a manner that six flues are spared out, starting from the fire-boxes and meeting in the centre in a vertical flue, and the faces which are intended to become black are left exposed in the setting. Thus for building purposes the bricks are set flat, for paving on edge, always so that those faces laid outward in the construction are left uncovered in the kiln.

"When the heat in the kiln has risen so high that the bricks have passed into the vitrified state, several shovels of salt are thrown into every flue. In the intense heat the salt vaporises at once and covers the exposed faces of the brick with a very thin, hard glaze. At the same time a fresh charge of coal is supplied, and before the coal is completely ignited the fire-doors and chimneys are tightly closed and daubed up.

"The smoke thus produced has an effect similar to that in the blue smoking of the Belgian roofing-tiles with alder wood, though it is less intense. A blackening of the clay to the depth of several millimetres due to the reduction of the iron takes place; this action is augmented by the fluxes from the salt fumes that are filling the kiln, and a very dense and hard coating, dull glazed, and of the appearance of graphite, is produced on the faces of the bricks, thus creating a perfectly weather-proof exterior. This process is employed with brick not for the sake of the colour effect alone, but also on the most extensive scale for those products where the first consideration is resistance to weathering influences and mechanical abrasion, such as roofing and floor tiles."

"Some of the Rhine and Lorraine establishments make a yellow flooring tile, coloured with iron, consisting of a plastic refractory clay with sand and a large amount of lime as a flux. When these are smoked in saggars, a very good black is obtained. The addition of calcium carbonate in the shape of chalk or similar material, not only adds a flux to the body but also prevents warping and makes possible the production of exact surfaces. Experiments have shown the remarkable fact that mixtures of fire-clay with chalk show a minimum shrinkage when there is about 25 per cent of calcium carbonate." Egyptain blue (Laurie, Proc. Roy. Soc., 1914, A, lxxxix., 418) is crystallised CaO.CuO.4SiO2. It is formed between 800° and goo°, above goo° a green glass being obtained.

Glass can be coloured yellow with colloidal cadmium sulphide, and Horner (CHEMICAL NEWS, 1874, xxix., 66) has produced a yellow of this sort in a boric acid bead. It really would be a good thing if somebody were to take up the whole question of colours in the borax bead so as to determine which were due to colloids and which to true solutions; and also to find out definitely what chemical compounds cause the colour in each particular case. (To be continued).

PROCEEDINGS OF SOCIETIES.

ROYAL SOCIETY. Ordinary Meeting, March 18, 1920.

Sir J. J. THOMSON, O.M., President, in the Chair.

THE following papers were read :—

"A Form of Botrytis cinerea with Colourless Sclerotia." By W. B. BRIERLEY.

A form of Botrytis cinerea with colourless sclerotia is described. This was obtained by the isolation and growth of a colourless sclerotium, which was formed in a culture of a normal strain derived from a single spore. The primary origin of the change resulting in the albino form is located in the byphal mother-cell from which the initial colourless sclerotium arose. Morphological and physiological comparison of the new strain and its normal parent fails to reveal any difference save that of sclerotial pigmentation. This lack of colouring matter is correlated with presence of an oxydase of the laccase type and absence of a chromogen in those tissues which in the normal form contain the black pigment.

Lotsy's dictum that "certainty of purity is a conditio sine qua non to obtain proof of the existence of mutation in living beings" is accepted, and it is shown that such a state is possibly not realisable in the fungi. Anastomoses of mycelium are common, and give rise to heterocaryotic or heteroplasmic cells; this condition of protoplasmic combination being maintained by both sexual and asexual reproduction. New organic systems are thus formed possessing new physiological potentialities, and interacting with the environment to produce new morphological facies.

It is suggested that somatic fusions resulting in a change of genotypic values are the mechanism whereby evolution in the fungi has taken place. Single spore strains, or 'pure lines," may be heterocaryotic or heteroplasmic, and the structure of fungi is such that quantitative rearrangements of cell-content are possible, giving rise to so-called "mutations." These changes in genetic constitution are not true mutations, but the result of mechanical segregation in an impure stock.

The present case is interpreted in the light of this hypothesis.

"Preliminary Account of the Meiotic Phenomena in the Pollen Mother-cells and Tapetum of Lettuce (Lactuca sativa)." By R. R. GATES.

In a preliminary study of meiosis in the pollen development of lettuce, several points have appeared which have a general bearing on cytological conceptions and the problems of genetics. The exceptional condition has been found in lettuce, in which every intergrade occurs between pollen mother-cells and tapetal cells. Even synapsis has been observed in binucleate tapetal cells, which emphasises the physiological aspects of the synaptic contraction. The tapetal cells are peculiar in being often very much

April 9, 1920 iron-wire advocated in the combustion. Even when economy is considered, the advantages of using platinum wire are more than sufficient to warrant its use.

As regards the printing, errors are few and far between. On page 37 "homogeneous" should obviously read "homologous."

A pleasing and useful feature of the book is the summary at the end of each section, and generally the author may be congratulated on supplying a long-felt want.

CORRESPONDENCE.

"LECTURE EXPERIMENT UPON COMBUSTION."

To the Editor of the Chemical News. SIR,-The "phenomenon" described by Mr. Price in your issue of March 26 is not "of the nature of a gas-cap," the flame observed being that of ordinary combustion of Neither in this coal-gas burning in excess of air. instance, nor in the case of a gas-cap formed above an oil flame, is the gas "burning below its actual ignitionpoint." The true explanation of the formation of the flame is the one given by Mr. Price in his last paragraph. "The presence of the wire lowers the velocity of the mixed gases, and so allows the gas to burn, but the combustion cannot be transmitted to the uprising gas as its velocity is greater than the rate of propagation of burning." An explanation of the mode of formation of true gas cap and of the flame described by Mr. Price

will make their difference clear.

When an oil flame is introduced into an inflammable gas mixture, the latter ignites, and a flame passes through the mixture, continuing to burn until all the mixture has inflamed, even if the oil flame be removed. The heat produced by the burning gases is of itself sufficient to raise the adjacent unburnt gas to the ignition temperature. If the percentage of combustible gas be below the lower limit of inflammability, flame will not propagate, since a burning layer of gas will not produce the required amount of heat to raise the temperature of the contiguous layer of unburnt gas to the ignition temperature. Extra heat may be supplied by an external source, such as an oil flame, and the gas immediately surrounding the flame may then be kept at its ignition temperature with the help of this extra heat, and a gas-cap is formed. It will be seen that the gas-cap can only form round the oil flame, and can only persist while the latter is kept in the mixture. The increase in height of the cap with (1) a higher testing flame and (2) a higher percentage of inflammable gas is explained in this way, being due to the extra heat provided, with the heating up of a larger quantity of gas to the ignition temperature.

The fact that the flame described by Mr. Price persisted without the assistance of external heat at once distinguishes it from the gas cap. The experiment described is similar to the well-known experiment illustrating the principle of the Davy safety lamp. If a piece of wire gauze be placed above the mouth of a Bunsen burner, the gas stream may be ignited above the gauze, but will not strike back through the gauze. In this present experiment the wire acts as a "gauze" of a single strand.

The usual appearance of the Bunsen flame is due to the fact that the gas mixture issuing from the burner tube contains insufficient oxygen for the complete combustion of the coal-gas. All the available oxygen is burnt up at the inner cone of the Bunsen flame, and the excess of coal gas is burnt as it comes into contact with the oxygen of the outer air. In the experiment described, the gas issuing from the burner tube mixes with the required external air for

NOTES.

THE "PRECIOUS" AND "RARE" METALS.-The ores of Sudbury, Ontario, carry platinum, palladium, and other metals of the platinum group, also gold and silver. The latter two, when spoken of collectively, are usually referied to as the "precious metals," and for clearness sake, platinum, palladium, &c., may be called "rare metals." are at the present time In point of value "rare metals worth per ounce six times as much as gold, and one hundred times as much as silver. Exact figures cannot be given for the precious and rare metal contents of the mattes produced at Sudbury, as these undoubtedly vary from year to year, being to some extent dependent upon the class of ores smelted. Certain deposits of the rocky type are richer in these constituents than the more massive ore bodies, and the whole subject of the association and method of occurrence of platinum, and especially of pal. ladium, in the Sudbury ores, is as yet not thoroughly understood.

For the three years ending in 1915 the average contents of the precious and rare metals in the Canadian Copper Company's mattes were o'10 ounces platinum per ton, o'15 ounces palladium, o'05 ounces At this rate, the mattes gold, and 1.75 ounces silver. produced by the company in 1916, amounting to 56,405 tons, are estimated to have obtained 5640 ounces of platinum, 8460 ounces of palladium, 2820 ounces of gold, and 98,709 ounces of silver. Of the precious metals a greater proportion is actually recovered than of the rare metals. For example, in 1916, as is shown in a table, the gold recovered amounted to 3495 ounces and the silver to 110,285 ounces, in each case considerably more than the theoretical contents based on the average of the three preceding years, while of platinum the yield was 1016 ounces, of palladium 1345 ounces, and of rhodium metals 257 ounces.

HINTS ON WORKING ALUMINIUM.-In response to numerous enquires they have received from works foremen and operatives on the subject of working in aluminium, the British Aluminium Company, Ltd., have prepared a series of booklets to supply the desired information in a concise and handy form. These booklets are comprised in a series called "Hints on Working Aluminium," each booklet dealing with a specific branch of the subject. They can be obtained by persons interested on application to the British Aluminium Company, Ltd., 109, Queen Victoria Street, London, E.C. 4, who will also be glad to give any further information required which is not covered by the series of booklets.

THE Spring Meeting of the American Chemical Society will be held with the St. Louis and University of Missouri Section in St. Louis, April 13 to 16 inclusive. Every indication points to the fact that the meeting will be one of the largest and most interesting ever held in the West by the American Chemical Society. St. Louis is the centre of the rapidly growing Middle West, and contains large and varied chemical interests. It has always been the leading drug centre of the West, and leads the country in the production of synthetic pharmaceuticals, alkaloids, and anæsthetics. St. Louis possesses all the units of a balanced self-sufficient chemical industry. It is a centre for ceramics, glass, paint, lead, and zinc manufacture. The following excursions are planned :- Laclede Byproducts Coke Plant; Monsanto Chemical Works, East St. Louis Plant; Laclede-Christy Clay Products Plant; Standard Oil Refinery, Wood River, Ill.; and Illinois Glass Company, Alton, Ill. The membership of the American Chemical Society has increased from 5603 in 1311 to 13,686 in 1919.

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NEWS

THAT all quiescent matter is only apparently inert as regards the movement of its parts is pretty generally accepted, but there is an absence of direct evidence of certain types of movement, in particular rotational as connoted by the expression: one body rotating round another.

It is true that a study of the movements of the beavenly bodies reveals various types of activity, including the foregoing one, and these are assigned to negative electrons under varying conditions. Inasmuch as man stands midway between two great systems of activity, it is reasonable to suppose that the atomic universe is not so different from the stellar universe as to involve a different system of mechanics; yet, there is the possibility of having to deal with what might be termed a complementary system of electrodynamics when formulating the activities of electrons or even atoms and molecules, should these entities be in a sufficient state of electrical unbalance.

The following statements from Jeans' "Report on Radiation and the Quantum Theory," p. 48, in a sense summarise the present position of uncertainty with regard to the interpretation of certain cognate phenomena. The numbers introduced, for purposes of reference, are mine. Thus, according to this view, which is supported by much greater volume of evidence than can be referred to bere-(1) The hydrogen atom consists of a negative electron revolving in an orbit round a positive nucleus of equal charge, while the helium atom consists of two electrons revolving in orbits round a nucleus with a positive charge equal in amount to twice that of an electron. (2) The inability of the Newtonian mechanics to explain line spectra becomes evident if we fix our attention on the hydrogen atom, which consists of two point charges only, one positive and one negative, and yet gives the highly complicated spectrum associated with hydrogen. (3) We are at once led to inquire why these two charges continue rotating round one another, instead of falling into one another, as the energy of their motion is dissipated by radiation. And how can such a simple system give a spectrum containing so many lines? The number of degrees of freedom of the system is only six, three of which represent its ability to move in space. How, then, can so many vibrations be possible? (4) And, again, why does not the energy of these vibrations appear in the measure of the specific heats? To all these questions the Newtonian mechanics can give no answer, The answer given by the quantumtheory is, perhaps, only partial, but, as we shall see, it is So convincing that little doubt can be felt of its fundamental accuracy."

It is of course possible that one may eventually come to regard energy as having an entity characteristic that cannot be perceived by itself, and it is only the effect of this energy, acting through the agency of matter proper, that makes itself known; consequently, unless ore has suitable apparatus to be acted upon by such energy, the apparent state of inertness is manifest. This statement obviously belongs to the domain of speculative philosophy. If, however, this idea be true, then it is the energy itself that may only move in some cases, in which circumstance a

quantum of energy is not after all such an absurdity. The somewhat advanced idea is, that rotational energy can only increase or decrease in steps, so that when a body rotates with n r.p.s. its energy is always a wholenumber of times the product hn, h being Planck's con stant. There are, however, very serious difficulties which stand in the way when radiation is involved. The revolving electron is, nevertheless, suggestive of some such action.

Referring now to Jeans' statements, considering (1) the question to be asked-Is there any directly-observed case known in molecular physics of one body rotating round another? In the study of literature on molecular phenomena, I cannot find a satisfactory answer to this question; but in my own experience there appears to be an answer.

Suffering occasionally from eye-fatigue, possibly involving some abnormal condition in the eye, I have often noticed when awakening in the morning with the eyes turned towards a bright white ceiling, groups (sometimes many groups covering the entire ceiling) of sharp black round spots revolving uniformly round each other at about 160 r.p.m. These spots are about equally spaced and of uniform blackness. The effect disappears very quickly and it has to be preconceived to be observed properly. No doubt eye specialists could furnish interesting examples of this kind.

This is not of course an orbital-electronic movement, but it is certainly a uniform rotational movement, of the above-mentioned type, of something in the eye, presumably particles of like molecular or atomic composition, rendered visible by some such phenomenon as occurs when X-rays are reflected from crystal planes. This effect may involve light absorption or interference in the eye, as distinct from what might be described as a converse resultant action when X-rays are synchronously reflected from planes rich in atoms. However this may be, the similarity of X-rays and white light is made suggestively apparent. It is now believed that white light consists of irregular pulses which become transformed into trains of sine-waves by the optical apparatus itself (see Wood, "Phyical Optics," 1914, p. 648). That X-rays have also this characteristic, in so far as they originate as irregular pulses, is probable, judging from the experiments and views of the Braggs and others, whilst Stokes' pulse-theory of X-rays is generally accepted. For a statement of this theory, based upon the sudden stoppage of a moving electrified particle, see Crowther, "Ions, Electrons, and Ionising Radiations," 1919, p. 143. The penetrating power of X-rays is of course due to their exceedingly short wave-length.

It seems to me that the eye-effect opens up a potential field of experiment with white light and organic or transparent matter in which movements are supposed to take place, since it ought to be possible to get a moving picture of what is going on in masses of matter in which life activity is known to exist. By some such method of investigation one can almost expect the mechanism of life to be formulated, very much as the mechanism of the atom is now being explored, and the knowledge gained in one such field of research should be of great value to the workers in other fields.

There are of course Brownian movements which may result from relatively finer-grained movements, and the microscope has revealed many coarse-grained movements, but so far as I know, there is nothing on record of actual "molecules" or particles in uniform rotational movement round each other. (See Perrin, "Atoms," chapter iii., iv

* The expression, a plane rich in atoms, is best understood by ing straight lines through the dots to intersect different numbers. arranging a group of equally-spaced dots on a piece of paper and drawThe line which cuts through the greatest number of dots represents a plane particularly rich in atoms. By further construction, when wave pulses strike into or across a mass of dots (atoms) it will be seen how it is that those waves (secondary ones-diffracted pulses) which originate from given sets of planes reinforce one another, and it is by this action that small pencils of light emerge from the crystal and produce the spots on the photographic plate. See W. H. Bragg and W. L. Bragg, "X-rays and Crystal Structure," 1918, Chap. xii.; see also Tutton, CHEMICAL NEWS, 1913, cviii., p. 301.