Addition Of Sulphuric Acid Research Articles

The mercuration of pyridine‐N‐oxide (ii)

AbstractPyridine‐N‐oxide has been mercurated with different reagents, i.e. mercuric acetate in acetic acid, mercuric sulphate, mercuric sulphate in sulphuric acid, mercuric chloride and mercuric bromide.Mercuration with mercuric acetate in acetic acid yields mainly derivatives substituted at positions 2 or 2 and 6, together with the compound substituted at the 3‐position. It is shown that the supposition of Ukai, Yamamoto and Hirano4 that the compound substituted at position 4 is formed in this reaction as the chief product, is incorrect.The 3‐ and 4‐isomers are obtained together with the 2‐isomer as chief product, however, when pyridine‐N‐oxide is heated with mercuric sulphate. Addition of sulphuric acid lowers the yield of this mercuration and changes the substitution pattern. Together with the derivative substituted at position 2 a considerable amount of the 3‐isomer is formed. Also in mercuration with mercuric chloride and mercuric bromide the nucleus is attacked at the 3‐ and 4‐positions, but here the reaction mixture consists preponderately of the 2‐isomer again.

A study of the mechanism of photochemical electron transfer processes in solution

The flash photolysis of halide solutions yields unstable species believed to be the dihalide ion the absorption spectrum of which we have observed and photographed. This transient has been noted during the photolysis of ( а ) the aqueous solutions of KCl, KBr, KI, HCl, NaCl, NaBr, NH 4 C1, MgCl 2 , HgCl 2 , CaCl 2 and SrCl 2 , ( b ) the ethyl and methyl alcoholic solutions of KBr and KI, ( c ) the methyl cyanide solution of KI. The effect of the addition of sulphuric acid, potassium hydroxide and Mn 2+ ion to certain of the solutions has also been studied. Our interpretation of the results of the flash photolysis of KI in solution, based on the Rigg & Weiss mechanism of electron transfer, involves the postulation of the splitting of the solvent molecule. In water solution, this would mean the formation of hydrogen. The production of hydrogen in aqueous solutions of KI of pH 6 to 7 has been confirmed by an investigation of the steady state photolysis.

THE PRODUCTION OF ANTIBIOTICS IN SOIL

Conditions affecting the production of gliotoxin by a strain of Trichoderma viride, known to produce this antibiotic in synthetic culture media, were studied in two types of soil, a highly acid, sandy podsol from Wareham Heath and a less acid garden soil. High yields of an antibiotic substance, which results from bioassays showed to be similar to gliotoxin, were obtained from both inoculated soils when autoclaved and supplemented with organic material. The autoclaved soils behaved differently when unsupplemented; Wareham soil supported production of the antibiotic but little or none was produced in the garden soil. No antibiotic activity could be demonstrated in soil which had not been inoculated with T. viride.Acidification of unsupplemented garden soil by addition of sulphuric acid had a favourable effect on production of the antibiotic, but raising the pH of Wareham soil by addition of calcium hydroxide also increased the yield. These effects, therefore, cannot be due simply to the change in pH of the soil.The beneficial effect of autoclaving the soil on production of the antibiotic assumed to be gliotoxin was analysed and separated into three distinct effects, elimination of the microflora, increase in availability of nitrogen compounds and increase in available carbon compounds. The last effect was considered to be of greatest significance.The antibiotic was produced in normal Wareham soil if supplemented with additional carbon compounds, but not in garden soil unless this had also been acidified before inoculation. A chromatographic method of bioassay used in the later work gave more substantial evidence that the antibiotic produced in the soil was, in fact, gliotoxin.

The Effect on Wool of Boiling in Aqueous Solutions I‐Solutions at pH 1.5–9 with and without Sodium Sulphate

Wool of 64s quality, in the form of yarn and cloth, has been given boiling treatments of 3 hr. with 50 min. for raising to the boil to imitate prolonged commercial dyeing processes but without the addition of dye. The pH of the solutions has been controlled at selected pH values between 1.5 and 9 by the gradual addition of sulphuric acid or sodium carbonate during the boiling. The wool has subsequently been examined for modification by means of determinations of alkali solubility, soluble nitrogen, disulphido sulphur, total sulphur, breaking load air‐dry and wetted with water, extension at break, abrasion resistance, and loss in weight. A smaller quantity of 56s Corriedale wool has been treated concurrently though subjected to fewer tests. The conclusions reached are‐ (1) the wools have suffered minimum modification when boiled at pH 3–3.5; (2) sodium sulphate, in concentrations up to 9.2 g./litre, has shown relatively little effect on the wool within the pH range 1.7–6.8, but above pH 6.8 the presence of sodium sulphate has caused alkali damage, which increases rapidly with increase of salt concentration and rise of pH; (3) a strong correlation has been found between disulphidê content and wet breaking load for treatments having pH values above 4; a similar correlation has been found to apply to abrasion resistance after about 20% of the original disulphide sulphur has been broken down; (4) alkali solubility and soluble nitrogen have shown a strong correlation with abrasion resistance and to a lesser extent with wet strength for treatments having pH values below 2.5. The practical implications are discussed.

THE HISTOCHEMISTRY OF LIPOIDS IN ANIMALS

Summary1. The available methods for histochemical analysis of lipoids having been reviewed, the following are regarded as valid for the substances or groups indicated: Sudan black: all liquid or grease‐like lipoids.Nile blue sulphate: ‘acidic’ lipoids (lipines, chromolipoids and free fatty acids) as against ‘neutral’ ones (hydrocarbons, triglycerides, higher alcohols, waxes, steroids, carotenoids, etc.).Fluorescence (without the addition of sulphuric acid): a rapidly fading green is due to vitamin A.Presence of spherocrystals: lipines, cholesteryl esters (and perhaps other sterol esters as well).Osmium tetroxide, primary blackening only: for active unsaturated bonds, most usually ethylenic linkages in fatty acid radicles and probably in carotenoids, but also for aldehyde groups (in plasmal), and for various other strong reducers which are not lipoid.Acid haematein test: phospholipines (possibly acetalphosphatides as well).Feulgen's plasmal test (not the Feulgen‐Verne test): acetalphosphatides by means of the aldehydes liberated from them.Schultz's method I (modification of Liebermann's reaction): cholesteryl group. Schultz's method II (modification of Lifschiitz's reaction): without a previous oxidation, for certain ill‐defined oxidation products of sterols, with a previous oxidation (by light and air, or by ferric compounds) for the cholesteryl group.Antimony trichloride, and glycerol dichlorhydrin: a transient blue or blue‐green is specific for carotenoids.2. Some of the above tests are subject to interference by certain rare substances; the plasmal test and Schultz's method I may possibly give positive results with certain toad poisons.3. The following tests are rejected as definitely invalid, insufficiently investigated, or superseded by more satisfactory techniques:Fischler's technique for fatty acids;Casanova's reaction;Ciaccio's methods I and II for ‘lipoids’The Smith‐Dietrich method for phospholipines;Romieu's method for lecithin;The Feulgen‐Verne technique for plasmal;Bennett's method for ketosteroids.

A Further Study of the Reactions of Fish to Toxic Solutions

ABSTRACT This paper records some further observations on the reactions of fish to toxic solutions. The method of experimentation resembles that described in a previous paper by the writer (Jones, 19476). In every case the solution is presented as an alternative to the Aberystwyth tap water, which is well aerated, very soft, of pH 6·8, In experiments with sodium sulphide a supply system is arranged in which dilute sodium sulphide solution, brought to pH 6·8 by the addition of sulphuric acid, is automatically made up as it runs into the observation vessel. Gasterosteus aculeatus L. reacts negatively to a 0·001N solution almost immediately; at greater dilution the ‘reaction time’ lengthens, at 0·00008N is about 47 min. Over the concentration range tested the reaction time is always shorter than the survival time. Gasterosteus is positive to 0·04N lead nitrate. As a positive reaction is also displayed to equivalent concentrations of calcium nitrate, sodium nitrate and sodium chloride it is possible that the osmotic pressure of the solution is its attractive feature. At 0·01 N the positive response to lead nitrate disappears and at 0·004N is replaced by a very definite negative reaction which is maintained down to 0·00002 N. The minnow (Phoxinus phoxinus L.) is also negative to dilute lead nitrate and will detect and avoid a 0·000004 N solution. Gasterosteus will avoid water more acid than pH 5·6 or more alkaline than pH 11·4. Over the range 5·8-11·2 the fish are indifferent or very vaguely positive. Gasterosteus is negative to 0·04 and 0·01 N ammonia solution, positive to 0·001 and 0·0001 N. The general result with ammonia is thus the converse of that observed with lead nitrate.

The production of substituted acrylic acids from ketone cyanohydrins

AbstractA reaction has been discovered by which ketone cyanohydrins CHR·CR'(OH)·CN may be converted into substituted acrylic amides, CHR: CR'·CO·NH2. The reaction proceeds under the influence of concentrated sulphuric acid via the addition compound of this with the cyanohydrin, CH3R·CR'(SO4H) ·CO·NH2. The addition compound splits out sulphuric acid again on heating, yielding the acrylamide. The formation of acrylamides does not occur with aldehyde cyanohydrins. Some suggestions are made to explain the formation of acrylamides from ketone cyanohydrin—sulphuric acid addition compounds.

Ultramikroanalyse II Die extinktiometrische Bestimmung des Magnesiums

The experimental technique employed in the determination of magnesium by means of tropaeolin 00, according to the method of Lang4), is discussed, and several sources of errors are pointed out. The solubility of magnesium tropaeolinate in water was determined; the saturated solution was shown to contain 3.25 × 10−7 g magnesium per cm3 at 20°C and about 2 × 10−7 g magnesium at 0°C.A convenient method for the determination of minute quantities of magnesium (10−5 to 10−7 grams) was worked out. According to this method magnesium is precipitated with a known quantity of tropaeolin 00, the precipitate is separated by centrifuging and the excess of dye is estimated by measuring the extinction of a portion of the supernatant liquid after the addition of sulphuric acid.

ON THE PRESERVATION OF THE STANDARD SOLUTION OF OXALIC ACID AND ON THE READING OF THE BURETTE

Abstract (1). The standard solution of oxalic acid should always be kept in a reagent bottle carefully wrapped with black paper. The solution thus preserved does not change its strength, irrespective of the presence or absence of sulphuric acid. Hence the old standard solution kept in a black bottle can as well used for titration. (2). The method of preservation of the oxalic acid solution, described in Treadwell’s “Analytical Chemistry” is not appropriate; the addition of sulphuric acid is not only unnecessary but objectionable, because the velocity of decomposition of the oxalic acid solution kept in a colorless bottle, becomes greater with the increase in the concentration of sulphuric acid added. (3). A convenient device for the correct reading of the burette is described.

On the boiling-point of aqueous solutions of nitric acid at different pressures. Part II.—The influence of water-retaining agents on the composition of the mixture of maximum boiling-point

Abstract 1. 1. The influence of the presence of potassium acid sulphate and sulphuric acid on the boiling-points of aqueous solutions of nitric acid has been studied at atmospheric and diminished pressures. 2. 2. It has been found that, while the presence of potassium acid sulphate brings about little or no change in the composition of the mixture of maximum boiling-point, additions of sulphuric acid to aqueous solutions of nitric acid cause a decrease in the nitric acid content of the mixture of maximum boiling-point, the decrease being greater the greater the addition of sulphuric acid. 3. 3. Diminishing the pressure has also been found to cause a slight further decrease in the nitric acid content of the mixture of maximum boiling-point. 4. 4. The results obtained show clearly why aqueous solutions of nitric acid can be concentrated to over go per cent. by distillation with concentrated sulphuric acid.

V. On the normal paraffins.—Part IV

In the last communication made by one of us on this subject (Phil. Trans., 1880, p. 451), it was stated that we contemplated making a joint investigation on the heptane from Pinus Sabiniana . A large quantity of the pure heptane was treated with chlorine in the manner described in this series of communications (Phil. Trans., 1872, p. Ill), and the chlorides boiling between 143° and 157°·5 were converted into the alcohols in the ordinary way. The primary alcohol boiled between 165°—170°, whilst the secondary alcohol distilled over, for the most part, between 156°—15 8°. The alcohols were then oxidised in the manner described in Phil. Trans., 1872, p. 121. The ketone obtained from the secondary alcohol was further oxidised by being heated with the chromic acid solution in sealed tubes at 100°. The liquid was then neutralised and the unattacked ketone was separated by distillation. In order to isolate the acids contained in the residue small quantities of sulphuric acid were added, and the acid which separated out (pentoic acid) was distilled off in a current of steam—the operation being repeated until the pentoic acid was no longer recognisable by its smell. The acetic acid contained in the residue was then separated by a further addition of sulphuric acid and distilled off by direct heating. The respective silver salts of the two acids were then prepared from the several fractions in the ordinary way. Analysis showed that the separation of the acids was complete. I. Silver salt from the normal alcohol. ( a ) 0·4035 grm. salt gave 0·1842 grm. Ag = 45·6 per cent. ( b ) 0·210 grm. salt gave 0·0953 grm = 45·4 per cent. Calculated for silver heptoate 45·5 per cent.

III. On a crystalline fatty acid from human urine

The occurrence of fatty matter in urine is a somewhat rare phenomenon, and is generally considered as a symptom of disease, or at least of an abnormal state of the system. In most cases it is found associated with albumen, forming the so-called “chylous urine,” in which the fatty matter is suspended in such extremely minute particles as to give the liquid the appearance of milk. In a few instances it has occurred in the shape of fluid oil-globules floating about in the urine; but it is more frequently found enclosed in cells, which sink and form a deposit at the bottom of the vessel. Fatty matter is a constituent of kiesteine , the pellicle which is sometimes formed on the surface of the urine of pregnant women, ant fat resembling butter was obtained from it by Lehmann, though by some authors the very existence of kiesteine as a peculiai deposit is doubted. Lastly, a few cases are described in which a fat-like substance was passed with the urine in the form of small concretions, which, when fresh, were soft and elastic, but dried into hard, yellow, wax-like masses (Heller's urostealith ). In no recorded instance was the fatty matter contained in the secretion in a state of true solution. The accounts which are given of the physical and chemical properties of the fatty matters of urine are extremely vague, and quite insufficient to enable us to identify them, so that it may be concluded that in most cases the quantity obtained was extremely small. Dr. Beale has, indeed, shown that the fatty matter which accumulates in the epithelial cells, passed with the urine in some cases of fatty degeneration of the kidney, contains cholesterine; and Berzelius and Lehmann state that urine, when distilled with the addition of sulphuric acid, yields butyric acid; but in other respects our ignorance is almost complete. None of the works devoted to the subject of urine contain a hint which would lead one to suppose that fatty matter in any form is a constituent of the ordinary healthy secretion.

On the use of the barometric thermometer for the determination of relative heights

1.1. The influence of the presence of potassium acid sulphate and sulphuric acid on the boiling-points of aqueous solutions of nitric acid has been studied at atmospheric and diminished pressures.2.2. It has been found that, while the presence of potassium acid sulphate brings about little or no change in the composition of the mixture of maximum boiling-point, additions of sulphuric acid to aqueous solutions of nitric acid cause a decrease in the nitric acid content of the mixture of maximum boiling-point, the decrease being greater the greater the addition of sulphuric acid.3.3. Diminishing the pressure has also been found to cause a slight further decrease in the nitric acid content of the mixture of maximum boiling-point.4.4. The results obtained show clearly why aqueous solutions of nitric acid can be concentrated to over go per cent. by distillation with concentrated sulphuric acid.