The oxidation was usually effected in from four to six hours.
Thus two experiments showed that the oxidation was not complete after 24 hours boiling with excess of permanganate.
If the solution be made alkaline however, the oxidation is completed in a few hours, yet the greatest difficulty still remains in the separation of the free acid from the products of oxidation in the solution.
The evolution of gas during the oxidationwould point to the same conclusion.
All these occur in the cacao bean as it comes from the pod, but why oxidationoccurs so much better in a fermented bean than in a bean which is simply dried is not very clear.
All recognise that for this oxidation the presence of three substances is essential: (1) The tannin to be oxidised.
Hoffmann discovered aniline and Perkin obtained mauve in 1856 by the oxidation of aniline with chromic acid.
The lights are formed, as in the insects, by the oxidation of material exuded by the fish.
In the case of the burning CO gas in contact with oxygen, the water acting as contact agent makes oxidation possible, enabling the main actors in the transformation to react upon each other.
The special point of interest, however, connected with this latter body as a product of trypsin-proteolysis is the fact that by simple hydrolytic decomposition, all chance of oxidation being excluded, it can break down into urea.
Some substances give a clear bead when heated and when cold, but appear enamelled when heated intermittingly or with a flame which changes often from oxidation to reduction, or with an unsteady flame produced by too strong a blast.
Borax dissolves it in the oxidation flame quite readily to a clear bead, which, with a considerable quantity of niobic acid, is yellow when hot, but transparent and colorless when cold.
With borax in the oxidation flame, it fuses to a clear dark red or violet bead, which retains its clearness when highly saturated with the oxide, or if heated with a fluctuating flame.
These different states of oxidation frequently present characteristic marks of identity sufficient to enable us to draw conclusions in relation to the substance under examination.
Borax dissolves it in the oxidation flame very readily to a clear bead, of a reddish-violet or dark yellow color, but yellow or light red when cold.
It is covered in the flame of oxidation into a yellowish-white oxide, which is carried off sometimes by the stream of air which propels the flame.
The oxides of mercury are, in the oxidation and reduction flames, instantly reduced and volatilized.
The bead should first be submitted to the oxidation flame, and any reaction carefully observed.
Borax dissolves it, in the oxidation flame, upon platinum wire easily, and in great quantity, to a clear yellow, which becomes colorless while cooling.
Carbonate of Soda dissolves oxide of lead in the flame of oxidation upon platinum wire quite readily to a transparent bead, which becomes yellow when cooling, and is opaque.
Borax dissolves silver-oxides upon platinum wire in the oxidation flame but partially, while the other portion is reduced, the bead appearing opalescent after cooling, in correspondence to the degree of saturation.
Those metals which are volatile in the reduction flame, appear as oxides in the oxidation flame.
Borax dissolves it in the oxidationflame to a clear dark yellow bead, which is colorless when cold, if the metal is not present in great quantity.
Borax dissolves it in the oxidation flame upon platinum wire to a clear colorless bead which turns grey when heated upon charcoal, through the presence of reduced metallic particles.
The point of the blowpipe should only touch the flame, while the current of air blown into it must be stronger than into the oxidation flame.
The exposure of the ore to this action is continued sufficiently long to ensure the more or less complete oxidation of the ore particles.
The oxidation or burning of the sulphur will provide all the heat necessary to maintain the continuity of the process.
It must be admitted that often the upper portions of a lode present a strong appearance of fire agency, but exactly the same appearance can be caused by oxidation of iron and manganese in water.
Geraniol by oxidation goes into the aldehyde, citral, which occurs in lemons, oranges and verbena flowers.
Oxidation and de-oxidation proceed so quietly that the tenderest cells are fed without injury.
By putting on a tight coating of the black oxide we can prevent or hinder the oxidation from going on into the pulverulent stage.
Our war experience in the "Oxidation of Ammonia" is told by C.
The second set of bacteria change the ammonia over to nitrites and then a third set, the Amalgamated Union of Nitrate Workers, steps in and completes the process of oxidation with an efficiency that Ostwald might envy, for ninety-six per cent.
Runge in 1834 claims to have detected it in coal tar and called it kyanol, which after oxidation became an insoluble black pigment and known as aniline black.
The luminescence reduction and oxidation process can be demonstrated many times.
These facts can all be explained by regarding luciferase as a catalyzer which accelerates the oxidation of luciferin and by assuming that intensity of luminescence is dependent on reaction velocity, i.
While intensity of luminescence undoubtedly increases with increasing reaction velocity, the luminescence itself probably accompanies only one stage in the formation of a series of oxidation products.
Light, however, has never been reported to accompany the oxidation of homogentistic acid, although it does accompany the oxidation of some other organic compounds.
Exactly what this material is and why light accompanies its oxidation are the two more fundamental problems in the field of Bioluminescence.
We can determine this by finding out whether luciferase will accelerate the oxidation of a large amount of luciferin, for such is the test of a catalytic substance.
We have seen that Bioluminescence is an oxyluminescence, that the light is probably due to the oxidation of a compound, luciferin, in presence of air and water and that the oxidation is accelerated by an enzyme-like substance, luciferase.
The Mechanism of the Production of Light during Oxidation of Pyrogallol.
A film of oxide is formed over the surface, showing definitely that oxidation has occurred.
Thus, in the oxidation of phosphorus several intermediate oxides are said to be formed.
The principle of deferred activity and storing up of power, occurs also in vital and mental phenomena; potential heat is stored up in our food, and is afterwards evolved by oxidation in our tissues.
The more immediate cause of this power is the oxidation of assimilated food; and the source of power in the food is the heat of the Sun stored up in the plants and animals they have eaten.
Beyerinck's view that it occurs at the moment peptones are worked up into the protoplasm cannot be regarded as proved, and the same must be said of the suggestion that the phosphorescence is due to the oxidation of phosphoretted hydrogen.
The suggestion that it is due to the oxidation of a body excreted by the bacteria seems answered by the failure to filter off or extract any such body.
The energy liberated during the oxidation of the nitrogen is regarded as splitting the carbon dioxide molecule,--in green plants it is the energy of the solar rays which does this.
The purple bacteria have thus two sources of energy, one by the oxidation of sulphur and another by the absorption of "dark rays.
The work of the world is accomplished in largest part by the oxidation of carbohydrates, that is to say, of sugars and starches.
Any extraneous muscular movements are carried out in virtue of an increased oxidation of materials and the heat production rises above the level of the basal metabolism with increased muscular effort.
The total quantity of heat produced by the body is a measure of the intensity of the oxidation of carbohydrate, fat, and protein within the body.
This compound is said to form a fusible and malleable metal, that can be easily worked by the silversmith; it is also said to resist oxidation through atmospheric influences.
The temperature of the furnace is now lowered as much as possible, although not to such an extent that it will retard the progress of oxidation and absorption.
It is chiefly on this account, as well as its resistance to oxidation in air and water, that it is used for such a variety of purposes, not only of ornament and luxury, but also in a domestic way.
At the bar, he ordered a beer and used it to wash down anotheroxidation tablet.
And the oxidation pills; take one every three hours or smother in the poor, thin air.
It is also obtained by oxidising tannin with hydrogen peroxide, the other oxidation product being ellagic acid, and the two may then be separated as indicated above.
The tannage may also be effected by exposing pelt saturated with hydroquinone to oxidation by the air.
The sulphurous acid formed prevents oxidation of the product on evaporation.
Hydrolysis of the pentacetyl leucotannin, however, yielded gallic aldehyde, and oxidation yielded purpurotannin (a naphthalene derivative) in addition to ellagic acid.
It is not possible to lay down exact limits as to where denitrification ends and oxidation begins.
This oxidation is performed by the nitrifying microorganisms, and the process is known as nitrification.
The change is accompanied by the absorption of oxygen, one atom of which combines with two of hydrogen to form water, and a substance remains called aldehyde, further oxidation of which produces the acetic acid.
The action of light, they explain, is due to the gradual oxidation which is induced by the sun's rays in the presence of oxygen.
This oxidation may be carried on even beyond the stage of acetic acid (when no more alcohol remains to be oxidised), resulting in carbonic acid gas, which escapes into the air.
In many smaller streams the opportunity for oxidation is afforded by weirs and falls.
Until recently this chemical action and the double mechanical action were believed to be the complete process, and its efficiency was tested by chemical oxidation and alteration, and absence of the suspended matter.
But we may say here that by nitrification is understood a process of oxidation of elementary compounds of nitrogen, by which these latter are built up into stable bodies which can do little harm in drinking water.
When the oxidation is completed the vinegar is drawn off, and the membrane is collected and washed, and is then again ready for use.
The process set up by the lactic ferment is simply a decomposition, an exact division of one molecule of sugar into two molecules of lactic acid, there being neither oxidation nor hydration.
It ought not to remain long out of fermenting liquid, nor ought it to be allowed to over-perform its function, for thus having oxidised all the alcohol it will commence oxidation of the vinegar.
Winogradsky concluded that the oxidation of nitrites to nitrates was brought about by a specific organism independently of the nitrous organism.
The final oxidation products of the carbon and hydrogen are carbon dioxid and water, which result from the decomposition of the carbonic acid.
Benzene is very stable to oxidants, in fact resistance to oxidation is a strong characteristic of the benzene ring.
It can be prepared by the oxidation of toluene, benzyl alcohol, benzaldehyde and cinnamic acid; by the oxidation of benzene with manganese dioxide and concentrated sulphuric acid in the cold (L.
On oxidation with nitric acid it is converted into benzaldehyde, whilst chromic acid oxidizes it to benzoic acid.
C6H5) with zinc and acetic acid; or by the oxidation of hydrobenzoin (C6H5.
But oxidation is always going on in the body by means of respiration and the circulation of the blood.
It yields an anilide; oxidation converts it into mesotartaric acid.
Each alloy should also be analysed after the process if there is any risk of its composition having been altered by oxidation or otherwise.
FeS2, are smelted with appropriate fluxes in a hot blast, without preliminary roasting, the sulphur and iron of the pyrites giving sufficient heat by oxidation to liquefy both slag and metal.
Absence of signs of rust or oxidation of a bright steel blade, after plunging it deep into the tissues.
