Marckwald and Foizik, by a complex volumetric process, find for this atomic weight the value 127.61 (Ber., xliii., 1710). The data are too bulky and complicated for reproduction here. The purpose of the investigation was not so much to determine the atomic weight exactly, as to ascertain the cause of the low value found in several previous researches. Flint has continued the work reported by Browning and Flint in 1909 on the fractionation of tellurium by hydrolysis of the tetrachloride (Am. Journ. Sci., 4], xxx., 209). The unfractionated material, by the basic nitrate method, gave Te 127 45. Progressive diminution of the atomic weight was noted in a series of fractions, namely, the fourth, eighth, and tenth. The tenth gave low atomic weights as shown in the following table : The apparatus here described under the name of porometer is similar in principle to that devised in 1873 by N. J. C. Müller, but differs from it completely in construction. By a simple arrangement a current of air is drawn through the stomata of a living leaf, its velocity being measured by the fall of a water-column. At a constant pressure the rate of air-flow is necessarily dependent on the size of the stomatal pores, and it is accordingly found that agencies such as darkness or loss of watersupply, which are known to diminish stomatal aperture, cause a striking drop in the rate of air-flow as recorded by | the pyrometer. In studying the effect of severing the leaf stalk and thus cutting off the water-supply, it has been proved that the first effect of withering is a wide opening of the stomatal pore, confirming F. Darwin, in Phil. Trans., 1898, B, cxc., 548. The porometer has been found of value in attacking the question of the causal relation between stomatal aperture and transpiration. This subject, on which a large number of observations have been made, will be fully treated else. where. In the present paper a single experiment is given illustrating the parallelism between the transpiration rate and the condition of the stomata as revealed by the poro meter. "Memoir on the Theory of the Partitions of Numbers. Part VI. Partitions in Space of Two Dimensions to which is added an Adumbration of the Theory of Partitions in D.Sc., LL.D., F.R.S. Space of Three Dimensions." BY MAJOR P. A. MACMAHON, In this part I consider the partitions of a number, the parts being placed at the nodes of an incomplete lattice in two dimensions. Thus, the lattice being of the nature depicted the parts are in descending order of magnitude in each row and in each column. The enumerating generating function is required. It is found that for a lattice of given specifica. tion and a given restriction upon the part magnitude the generating function satisfies a functional equation. From this the functional equation satisfied by the corresponding inner-lattice function, as is defined in Part V., is deduced. This investigation then turns upon the determination of the fundamental solutions of this equation and the expression of the generating function by means of them. The complete solution of the problems in hand is thence obtained, and the inner-lattice function is shown to be expressible in an elegant determinant form. At the end of the paper the subject of three-dimensional partitions is broached. It is shown that the method of of partition at the summits of a cube is worked out in lattice functions is again available, and the particular case detail from this point of view. The further investigation of this interesting question is reserved for a future communication. "The Kinetic Theory of a Gas Constituted of Spherically Symmetrical Molecules." By S. CHAPMAN. This paper may be regarded as a sequel to Maxwell's kinetic theory of a gas whose molecules repel one another according to the famous fifth-power law (Phil. Trans., 1867). Maxwell's deductions from his hypothesis were found not to agree with fact, but the theory was valuable because it was the only mathematically rigorous kinetic theory in existence. When he wrote a later paper on the same subject (Phil. Trans., 1879) he was aware of the defects of his assumption, but was prevented by certain analytical difficulties from generalising his theory by adopting a wider hypothesis. In this paper these difficulties have been very largely overcome. With the same rigour as in Maxwell's theory, formulæ are deduced for the coefficients of viscosity, diffusion, and thermal conductivity in a simple or com. pound gas. The molecules are assumed to be spherically symmetrical, but no particular kind of interaction is postulated. The latter, however, is involved in the formula by the occurrence, as factors, of two definite integrals. Certain relations may be deduced without the evaluation of these factors. The most interesting of these is 8 = ĝu Cv, where is the thermal conductivity, μ the viscosity, and C, the specific heat at constant volume. This formula, which was also obtained by Maxwell, has always been regarded as a special consequence of his hypothesis, whereas it only depends on the spherical symmetry of the molecules, and is true for rigid-elastic spheres, among other cases. In general, the formulæ can be completed only by the evaluation of the before-mentioned factors. In the paper this is done for the case of rigid-elastic spherical molecules, for centres of force repelling according to the inverse n-th power law of distance, and for the case of rigid elastic spheres surrounded by fields of attractive force. The last case furnishes a rigorous proof of Sutherland's formula for viscosity. and some important corrections to his theory are made. Finally, the formulæ obtained are compared with experimental results to test the accuracy of the various laws considered, and to obtain improved data concerning the molecules, and other physical constants of gases. · “Radiation in Explosions of Coal-gas and Air." W. T. DAVID, By "The Mechanical Viscosity of Fluids." By Dr. T. E. STANTON. The paper deals with the experimental determination of the ratio of the shearing stress to the rate of change of distortion in fluids which are in sinuous or eddying motion. Thus in a fluid in eddying motion flowing through a parallel pipe of circular cross-section, if F is the mean shearing stress on any cylindrical surface of radius r concentric with the pipe, and v the average velocity in the axial direction of the fluid in this surface, then writing dv F = μ' the object of the experiments was the deter mination of μ' as a function of the dimensions of the pipe and the velocity of flow. This ratio has been called by Osborne Reynolds "Mechanical Viscosity" to distinguish it from the corresponding ratio when the fluid is in steady or laminar motion, which is the ordinary coefficient of viscosity. dr The fluid chosen for the purpose of the experiments was air flowing at speeds up to 2200 cm. per second through pipes 5'08 and 7.35 cms. diameter. A small Pitot tube of width 0.25 mm., connected to a very sensitive gauge, reading to 0.005 mm. of water, has been used for measuring the distribution of velocity, and a second sensitive gauge has been used for the shearing forces. The results of the experiments are as follows: 1. In pipes artificially roughened so that air friction dr matical coefficient of viscosity V and the above product vc l. 3. In ordinary smooth pipes of different diameters, owing to the existence of a region of viscous flow at the boundaries, exact similarity between the distributions of axial velocity from centre to walls only obtains when the two viscosities (μ and μ1) are the same for each pipe. "A Silica Standard of Length." By Dr. G. W. C. KAYE. 17 that of silica over the ordinary range is about 0'4 x 10 -6, i.e., 1/20 of this amount. It is true that the best qualities of invar, M. Guillaume's nickel-steel containing 36 per cent Ni, have expansion coefficients comparable with that of silica, but experience has shown that while invar is eminently useful for working standards, it is quite unsuitable for primary standards, owing to its large thermal hysteresis. Fused silica, on the contrary, has been found to be practically entirely free from this defect; it enjoys, in the matter of cost, an enormous advantage over platinumiridium; furthermore, in view of the fact that primary standards are always handled by trained and skilled observers, its comparative fragility is of small consequence. Modern methods of manufacturing and working silica have rendered it possible to construct a silica line-standard metre. The present model, the first of its kind, consists of a silica tube into which are fused at its ends optically. The worked plane parallel slabs of silica. These carry the graduations, and their undersides are platinised. graduations, defining the metre length, are made by cutting through the platinum film with a ruling diamond. The platinum deposit permits the ruling of very beautiful cleanedged lines. The bar is supported at the Airy points so that the slabs are horizontal. The lines are viewed from above through the slabs, and are thus seen to advantage. The apparent length of the standard is independent of any change of tilt of the cover-slips which are used to protect the platinum films. The thickness and position of reference line lies in the "neutral plane" when the bar is the end slabs are so arranged that the image of each immersed in water. shrunk a little over half a micron in the process. It is The silica metre was annealed at about 450° C., and anticipated that its future secular variation will be negligible so far as practice is concerned. "The Proberties of Oil Emulsions. Part I. Electrical Charge." By RIDSDALE ELLIS, B SC. The electrical charge on the globules and the contact potential at the oil-water interface were obtained from measurements of the migration velocity in an electric field. The apparatus used by Whitney and Blake and by Burton for determining velocity of migration were found not to be accurate, since they did not take into consideration the electrical circulation which takes place, and other factors. ployed, and corrections for electrical circulation and other To avoid these errors a microscopic method was emeffects were introduced into the method of calculating migration velocity. For determining contact potential in presence of electrolytes it was found necessary to modify the apparatus in order to enable the evolution of gas at the electrodes to be avoided, which would otherwise prevent readings being taken. It was found that the magnitude of the contact potential at the oil-water interface is of the same order of magnitude for oils of various kinds whether very pure or containing large amounts of impurities. Further, the contact potential at the oil-water interface is of the same order of magnitude between the suspended particles of colloidal metals, lyco. as that at the glass-water interface and at the interface other considerations it would appear that the contact podium, quartz, and other substances. From these and potential in neutral solution depends almost wholly on the dielectric constants of the suspended particle and of the medium in which it is suspended. The contact potential at the oil-water and glass-water interface is a maximum in neutral or slightly alkaline solu. tions. Thus the addition of caustic soda at first increases the contact potential at the oil-water interface, but when The general properties of fused silica, and in particular the concentration exceeds o'oor N the contact potential is its remarkably low coefficient of expansion, render this diminished, rapidly at first, and then slowly. In the substance specially suitable for the construction of per-glass-water interface the maximum potential appears to be manent length-standards of the highest class. in neutral solution. If hydrochloric acid is added the contact potential is reduced very rapidly for small concentrations, but only slowly for comparatively high concen. trations. The coefficient of expansion of platinum-iridium, which has hitherto been the material almost exclusively employed in the best work, is about 9× 10-6 per degree C., while for its sum, and more generally it always has this ex pression for sum when the summation is performed in the Cesaro manner. The method employed is shown also to lead to results of analogous nature, previously known. It involves the study of certain parametric integrals and of a theorem in the theory of sets of points stated and proved in the paper, to the effect that if a set of points of positive content be shifted bodily a sufficiently small distance along the straight line on which it is situated, it necessarily coincides with its original position as to a sub-set of points whose content may be made as near as we please to the content of the set. "Mode of Generating Fourier Series." By Dr. W. H. YOUNG, F.R.S. "Pendulum Clocks and their Errors." By H. R. A. MALLOCK, F.R.S. The errors to which pendulum clocks are liable may be divided into three classes, viz. : 1. Those which may affect free pendulums oscillating in In good clocks, unexplained variations of rate are not uncommon, and may be as large as half a second a day, or even more. At any rate, a clock whose rate continues constant within 1/200,000 for a year or more is exceptional, and anything which succeeds in securing a constancy of rate better than 5 parts in a million may be considered an improvement. "Distribution of Slide in a Right Six-face Subject to Pure Shear." By E. N. DE C. Andrade. Major C. L. WILLIAMS, M.D. "Viability of Human Carcinoma in Animals." By nodules of Myrica gale." By Prof. W. B. BOTTOMLEY. "Structure and Physiological Significance of the Root "Surface Electric Charges of Living Cells." By H. W. HARVEY and W. B. HARDY, F.R.S. "Reflex Inhibition of the Knee Flexor." By Prof. C. S. SHERRINGTON, F.R.S., and Miss S. C. M, SOWTON. Septa in Plants with Reference to the Translocation "Origin of Osmotic Fffects. IV. Note on the Differentia Nutritive Materials." By Prof. H. E. ARMSTRONG, F.R.S., and Dr. E. F. ARMSTRONG. CHEMICAL SOCIETY. Ordinary Meeting, June 15th, 1911. Prof. PERCY F. FRANKLAND, LL.D., F.R.S., President, in the Chair. MESSRS. William Gidley Emmett, J. T. M. Dunlop, and A. W. Titherley were formally admitted Fellows of the Society. The PRESIDENT stated that the Council, at their meeting held that afternoon, had sealed an Address of Congratulation to His Majesty King George V. on the occasion of his Coronation, and an Address of Congratulation to the University of St. Andrews on the Celebration of the Five Hundredth Anniversary of the Foundation of that University. To His Most Gracious Majesty King George V. MAY IT PLEASE YOUR MAJESTY,-We, the President, Council, and Fellows of the Chemical Society beg leave to offer to your Majesty our sincere and most respectful congratulations on the auspicious event of your Coronation. We approach you with the more confidence when we remember how much the science of Chemistry and the position of our Society are indebted to the favours of your august House. We ever bear in mind that a Royal Charter was granted to the Chemical Society by Queen Victoria, and that the Royal College of Chemistry, which was so largely instrumental in fostering and developing the study of our science in this country, was founded by your illustrious Grandfather, the late Prince Consort. moreover, with special gratitude that we recall the lively interest which, as recently as two years ago, was taken by your Majesty and her Majesty Queen Mary in the International Congress of Applied Chemistry, when you extended the Royal welcome to the chemists of all nations assembled in the Capital. It is, the pursuit of all useful knowledge, may be promoted and We venture to hope that not only chemical research, but furthered in this realm under your benevolent and gracious In discussing the various sources of change of rate, all matters (as far as the author knows) which can alter the period by as much as 10- are taken into account. It appears that most of the anomalous changes of rate are due to variation of friction in the escapement and main-patronage, and we beg to assure your Majesty of our loyal taining mechanism, which acts chiefly, but not exclusively. by altering the arc of vibration. A graphic method is given for determining in detail the action of escapements on the period. "Ceratopora, the Type of a New Family of Alcyonaria." By Prof. SYDNEY J. HICKSON, F.R.S. "Sensibility of the Eye to Variations of Wave-Length." Bv W. WATSON. D.Sc., F.R.S. The author has compared the width of Edridge Green's monochromatic patch with the minimum change in wavelength perceptible as a change in hue in the yellow under exactly similar conditions, and finds there is a marked difference. It is also shown that an admixture of white light would not account for the increased sensitiveness when two monochromatic patches are compared. devotion as we do earnestly hope and pray that your Majesty's reign may be long, happy, and fruitful.—Signed on behalf of the Chemical Society, (Signed) PERCY F. FRANKLAND, President. G. T. MORGAN, Honorary HORACE T. BROWN, Foreign Secretary. Dated this the Fifteenth Day of June, One Thousand Nine Hundred and Eleven. To the University of St. Andrews. On the auspicious event of the Celebration of the Five Hundredth Anniversary of the Foundation of your University, we, on behalf of the Chemical Society, desire to offer you our most sincere and hearty congratulations. CHEMICAL NEWS, July 14, 1911 Purification and Properties of Acetic Acid. We share the world-wide interest which is evoked by the oldest and most picturesque of the Scottish Universities, and we rejoice to think that this ancient seat of knowledge should have so early recognised the claims of natural science as to establish a Chair of Chemistry already one hundred years ago. We congratulate you on your not having allowed the venerable traditions of the past to overshadow the urgent needs of the present, and we cordially admire the munificent and devoted generosity of your friends in raising the worthy buildings, equipped on modern lines, for the study of Chemistry. It is, moreover, with lively satisfaction that we have come to regard your Chemical School as an active and fertile centre of research, in which have been conducted a large number of valuable investigations, the results of which are embodied in the Transactions of our Society. We trust that the now happily accomplished absorption of the Dundee College by the University may prove of great mutual benefit, and that the blending of the young institution with the old may be a guarantee of continued | strength and fertility. In the name of the Council and Fellows of the Chemical Society we wish you all prosperity in the future, and we would express the earnest hope that the grey Town set by the Northern Sea may never cease to attract and inspire active workers, not only in our own science, but also in other branches of learning.-Signed on behalf of the Chemical Society, (Signed) PERCY F. FRANKLAND, President. HORACE T. BROWN, Foreign Secretary. Dated this the Fifteenth Day of June, One Thousand Nine Hundred and Eleven. The PRESIDENT announced that the Secretary of State had intimated his intention of making regulations dealing with the smelting of materials containing lead, the manu facture of red- or orange-lead, and the manufacture of flaked litharge, in accordance with a draft, copies of which may be obtained on application to the Factory Department, Certificates were read for the first time in favour of Messrs. Lionel Gowing Scopes. 3, Estcourt Street, Devizes; George Wishart, B.A., Royal School, Armagh. Home Office, London. A ballot for the election of Fellows was held, and the following were declared subsequently duly elected :Ernest Andrew Atkins; Norman Ernest Atkinson; Arthur Owen Blackhurst; George Arthur Bradshaw, M.Sc.; Arthur Frederick Clarke; Charles Ernest Cooke; Thomas Cowling; Ganesh Datta, B.A.; Rudolph Demuth; Benjamin Gallsworthy; Edgar Harold Gardner; Joges Chandra Ghose, M.A.; Cyril Herbert Koszelski Gonville; Rowland Lewis Goold; Edward Lionel Joseph; Henry Edmund Linenbröker; Herbert James Ling; Richard William Merriman, M.A.; Felix Gabriel Paul; Leonard Ison Pitt, B.Sc.; William Keighley Walton. Of the following papers, those marked * were read :*174. "The Alleged Complexity of Tellurium." By AUGUSTUS GEORGE VERNON HARCOURT and HERBERT BRERETON Baker. It has been asserted by Flint (Am. Fourn. Sci., 1910, [4, xxx., 209) that tellurium can be separated into two fractions by partial precipitation of the tetrachloride by water. Using 200 grms. of highly purified telluric acid, the authors have repeated the work. After four partial precipitations, Flint obtained a diminution of a whole unit in the atomic weight of tellurium, but the authors find that the atomic weight is not altered. The mean result of five determinations of the atomic weight of the fourth fractionation was 127:54, that of material similarly purified, but without the fractional precipitation, being 127:53. They 19 conclude that no separation is effected by this method, and that it is probable that Flint's material was insufficiently purified. DISCUSSION. Prof. ERNST COHEN said that he was extremely interested in the facts communicated by Dr. Baker, as they cleared up several doubtful points in some researches on the allotropy of tellurium which had been carried out during the last two years in his (the speaker's) laboratory. It had been known for a long time that allotropic forms of tellurium existed, but we have been entirely ignorant of the relations between them and of the conditions under which they could be formed. The measurements of Exner, Berthelot, Beljankin, and others in this direction, did not agree with each other, but an explanation of this disagree. ment was found in the fact that the allotropic change of one of these forms was markedly affected by light, which displaced the equilibrium. Flint's recent statements introduced difficulties which the authors had now removed, as they had shown that tellurium must still be regarded as a single elementary substance. appeared so mysterious, under the head of dynamical It was thus possible to bring all these phenomena, which allotropy. *175. "The Purification and Properties of Acetic Acid." By WILLIAM ROBERT BOUSFIELD and THOMAS MARTIN LOWRY. Acetic acid may be purified by distilling from potassium permanganate, using a still-head to retain acids of higher boiling-point, and then freezing to remove the water. The purified acid melts at 16 60°, and has a density of 1.05148 at 18°/4° and 1·04922 at 20°/4°; its maximum conductivity when mixed with water is K18 = 0.0016415. DISCUSSION. Dr. VELEY remarked that those workers who had been engaged in the purification of even the commonest acids could fully appreciate the difficulties encountered in preparing acetic acid free from its homologues, so as to obtain trustworthy data for its physical constants, such as electrical conductivity, melting-point, and density. oxidation with potassium permanganate appeared to be The method adopted for destroying the formic acid by of especial interest, as doubts had been expressed as to the statements contained in text-books that formic acid can be completely oxidised under these conditions. Dr WADE said that in purifying acetic acid for the preparation of esters he had succeeded in eliminating propionic acid and its immediate homologues by fractional distillation with a small quantity of water, with which it was perhaps not generally known that all the lower fatty acids, with the exception of acetic acid, formed volatile azeotropic mixtures. He employed. however, an evaporator still-head, which, as Young had shown (Trans., 1899, lxxv., 699). was much more efficient than the pear column employed by the authors. He doubted whether the oxidisable impurity observed by the authors was formic acid; it was well known that other oxidisable impurities were often present in commercial acetic acid. Dr. L. F. GUTTMANN stated that in the course of some experimental work on mixtures of acetic acid and acetic anhydride he had had occasion to prepare pure acetic acid. On attempting to do so by freezing a large quantity of "purest" glacial acetic acid, allowing it to thaw partially, discarding the liquid portions, and repeating this procedure five or six times, he had expected to obtain a glacial acetic acid of a high degree of purity; the analysis of this acid, however, gave over 100 per cent. Pure The normal solutions used were most carefully standardised, yet the result remained the same. acetic acid, giving a value of 100 per cent, was subsequently obtained by fractional distillation of the products; it therefore appeared as if pure commercial acetic acid might contain some acetic anhydride which could not be removed by fractional crystallisation. He wished to know whether the authors had had similar experiences. Dr. TITHERLEY pointed out that the reducing substance supposed to be formic acid might be gloxylic acid, which was a common impurity in acetic acid, and which would probably pass over in the earlier fractions on distillation. As glyoxylic acid in small quantities would account for the observations of the authors, he asked if any attempts had been made to prove the presence or absence of this substance. Dr. LowRY, in reply, said that the acetic acid was distilled in presence of a little water, but the quantity was not sufficient to carry over the higher homologues before the acetic acid as a minimum boiling mixture. The permanganate method of purification had the advantage that there was no real risk of producing any acetic anhydride; the acid was distilled while still moist, and was subsequently dried by freezing. The oxidisable impurity of low boiling-point might con tain glyoxylic acid, but the object was to get rid of it, and not to identify or isolate it. *176. "The Solubility of Carbon Dioxide in Beer." ALEXANDER FINDLAY and BUCCHOK SHEN. By July 14, 1911 manner on the funnel can be dried by means of this simple additional apparatus in a very short time. Besides dispensing with the trouble of transferring the precipitate to a desiccator, the apparatus saves much time in the drying. The drying is most rapid when a steady, not too rapid, stream of air is drawn through the apparatus by means of the filter pump after passing through a large drying tower filled with calcium chloride; further, the hood, which is made of blown glass or, for very rapid drying, of metal, can be warmed with a flame. The precipitate can, if desired, be dried under diminished pressure by affixing a screw clip to the air inlet of the drying tower. Another application of the apparatus is the drying of a precipitate in a non-reactive atmosphere; the gas can be circulated round and round, if necessary, by means of a blowing arrangement fitted to the filter-pump. This small inexpensive apparatus changes a Buchner funnel into an exceptionally efficient desiccator, which dries, not only precipitates collected on the funnel by the usual methods employed therewith, but also can be used conveniently for drying crucibles, &c., in a current of dry air. (We are indebted to the Chemical Society for permission to reproduce the accompanying illustration). *178. "The Action of Ammonia and Amines on 2-Phenyl and ERNEST CHISLETT HUGHES. 3-benzoxazine-4-one." BY ARTHUR WALSH TITHERLEY I: 2-Phenyl-1: 3-benzoxazine-4-one (I.) readily combines with ammonia, giving bright orange needles of salicylbenzamidine (II.), and primary amines, giving yellow derivatives (III.) of similar constitution : Previous experiments on the absorption of carbon dioxide by beer (Langer and Schultze, Zeit. fur das ges. Brauwesen, 1879, ii., 369) have been interpreted as showing that beer dissolves more carbon dioxide than the corresponding water-alcohol solution; and the supposed increase has been attributed to adsorption by the colloids present in beer (Enslander and Freundlich, Zeit. Phys. Chem., 1904 xlix., 317). These conclusions, however, are not in harmony with experiments carried out by Findlay and Creighton (Trans., 1910, xcvii., 536), and the authors now show that carbon dioxide is, as a matter of fact, less soluble in beer than in the corresponding water-alcohol solution, and that C6H4 the contrary conclusion reached by Langer and Schultze must be attributed to their having used beer supersaturated with carbon dioxide. *177. "An Addition to the Buchner Funnel." By ALFRED CHARLES GLYN EGERTON. The apparatus consists simply of a small glass hood, which can be connected to a drying tube. The glass hood is made of such a diameter that it fits inside a Buchner funnel, the joint being made air-tight with a rubber ring situated in a groove round the rim of the hood. It is well to employ a gentle pressure with the ring of a retort-stand to hold the hood in position, unless working with air under diminished pressure. A precipitate collected in the usual These amidine derivatives give colourless hydrochlorides possessing the cyclic constitution : which are very unstable, and readily lose ammonia or an amine, passing through the cyclic compound I. into Nbenzoylsalicylamide in presence of water. The free cyclic bases, which are intermediate compounds in the synthesis of the amidines II. and III., are too unstable to exist in the free state. Salicylbenzamidine (II.) may also be synthesised from phenyl salicylate and benzamidine, and o-hydroxytriphenylcyanidine also results as a secondary product. 2-Phenyl-1:3-benzoxazine-4-one combines with secondary amines, giving mixtures of labile isomeric cyclic and openchain compounds of the type IV. and V. : - CO NH O-CPh With dimethylamine no proper separation could be effected, but with diethylamine the colourless compound (IV.) was isolated. With diphenylamine a bright yellow compound (V.) was obtained, which, owing to steric influences, does not possess normal phenolic properties. It is probable that in all the yellow open-chain derivatives the molecule is bordering on ring-formation, and the colour is attributed to the disturbance of residual affinity thus created. Replacement of the hydrogen atom of the phenolic hydroxyl group by methyl in salicylbenzamidine leads to a colourless compound, the velocity of hydrolysis of which is normal as compared with similar amidines, |