It is permissible to assume that the irregularity exhibited by Neradol D as regards the analytical estimation of its tannin contents is connected with the low molecular weight of the tanning principle.
This synthetic tannin may be employed alone or in conjunction with other tannins, and yields a leather similar to that obtained by chrome tannage.
A further determination of the quality of a synthetic tannin is the capability of the latter of dissolving or precipitating the natural tannins.
Quite different properties are exhibited by sodium phenolsulphonate, which completely converts quebracho tannin into a water-soluble substance, the aqueous solution of which deposits no insolubles.
The crude synthetic tannin thus obtained has yet to be diluted and partly neutralised before it can be applied in practice, and this is carried out by mixing the crude product with strong caustic lye.
Another source of error is the swelling influence on hide powder by acids; for instance, an acid extract of vegetable tannins would show higher tannin contents in the analysis than would the same extract when less acid.
Analysis of the partly neutralised product reveals a tannin content of 17.
Among other contents of the cell, fatty substances and tannin are known.
The presence of tannin has been established in the case of a great number of freshwater algae.
The bark of various Australian species, known as wattles, is also very rich in tannin and forms an important article of export.
Directly he has done this the conjurer must be brisk in his movements, because after the tannin has been put in the water soon becomes slightly cloudy.
The object of pouring water into the first glass and tipping it back into the jug is to mix the tannin with the water in the jug.
A good process for the estimation of tannin in tea has been published by Allen (Chem.
Meals prepared from beans, horse-beans, and lentils, contain a tannin which imparts a green or black color to salts of iron.
The exact strength of the lead solution is to be determined by means of a solution of pure tannin of known strength.
The manuscript under examination is again spread upon a glass-plate, and a solution of tannin (or preferably, a solution of ferrocyanide of potassium containing one per cent.
Tannin forms from a fifth to a seventh of the weight of the dried tea leaf, and is the more completely extracted the longer the tea is infused, or “draws.
The tannin in ordinary tea tans, or hardens, the lining of the digestive organs, also the food eaten.
Tannin is a powerful astringent substance to tan skins into leather.
In the latter case a comparatively small percentage of tannin is extracted from the galls, while much is extracted with hot water and the consequence is, on adding the indigo blue the color is not brought out as it should be.
Clark's investigations seek to demonstrate the superiority of tannin and gallic acid over infusions of the natural galls, and he undertakes to determine the correct ratio of tannin and sulphate of iron to be used as ink.
It is advisable, however, not to discard tannin altogether, owing to the slow blackening of the gallic acid ink, and a little tanningives initial blackening and body, while it is absolutely necessary for copying ink.
The products of these thorn, trees were collectively used together as ink, most of the tannin being obtained from the pomegranate, and the gum from the acacia.
Blue-black tannin ink lost color, and the reducing nature of the tannin tended to the formation of a highly objectionable precipitate in the ink, which made writing anything but a pleasure.
Tannic acid is the best tannin for mordanting as it is the purest and is free from any other colouring matter; it is, therefore, used for pale and bright shades.
Cotton and linen are prepared with tannin after they have been through the required cleansing, and, if necessary, bleaching operations.
Cotton saturated with tannin attracts the dye stuff more rapidly, and holds it.
Cotton and linen strongly attract tannin and when prepared with it they are able to retain dyes permanently.
America; they contain 20 to 35% tannin and a brown colouring matter.
The tannin is readily soluble, and for this reason green tea especially should be infused for a very short time and never boiled.
It will be noticed that green tea contains twice as much tannin as black tea; during the fermentation which the black tea undergoes, some of the tannin is decomposed.
What effect has tannin upon the digestion of proteids?
Tannin in foods in large amounts may interfere with the normal digestion of the protein compounds, because it coagulates the albumin and peptones after they have become soluble, and thus makes additional work for the digestive organs.
In artificial extracts some such coloring matter as caramel or tannin is used.
A slight precipitate only should form due to the presence of a small amount of tannin normally present in this filtrate.
Unripe fruits contain a high percentage of tannin which, in the ripening processes of the fruit, becomes changed into cellulose and sugar.
This large percentage of tannin accounts for the prevalence of constipation among female tea drinkers.
Most people, who use these drinks would consider it a sin to go to a drug store, buy some pure tannin or caffeine, dilute it with water, sweeten it with sugar and drink it.
No one would drink tea or coffee were it not for the tannin and caffeine contained in them.
Tannin is a powerful astringent substance to tan skins into | | leather.
The tannin in ordinary teas tans, or hardens, the lining of | | the digestive organs, also the food eaten.
He gives a formula for a bromide paper, which is treated with tannin in order to absorb the bromine set free during exposure, otherwise the darkening would be very slight.
I then made some more, substituting for tannin potassium nitrite (not nitrate), which is colorless.
The tanninalso turned brown on keeping for a week or so.
Tannin Materials First and foremost under this heading are the nutgalls.
Moreover, the presence of the iron-tannin compound helps considerably to increase the fastness of the dyeing.
It is to the combined effects of the tannin substances and the dyewoods that furs dyed with vegetable dyes owe their beauty of color, lustre, naturalness of shade, permanence of the dyeing, and durability of the leather.
The use of the iron-tannin compound as a dye proved to be very effective, and to this day the production of blacks by means of the vegetable coloring matters has as a basis an iron-tannate.
The hemlock is valuable not only for the tannin of its bark, but as a wood for many purposes is equal to spruce.
From time immemorial, the substance employed to furnish the tannin to the hides of animals, in order to convert them into leather, has been oak bark.
The tanninof nutgalls, which is that generally employed for chemical purposes, is sometimes called gallo-tannic acid, to distinguish it from other species.
England, notwithstanding the distance, from the fact of its containing a greater per centage of tannin than any other bark.
Its tannindiffers materially from that of nutgalls.
The inner wood furnishes a kind of Catechu or Cutch, which contains much tannin and is a powerful astringent.
The substance from which pure tannin is most frequently obtained for chemical purposes is nutgalls, for tannin constitutes above 40 per cent, of their weight.
Tannin obtained from these sources, however, differs materially in some of its characters.
For ink-making thetannin has first to be transformed into gallic acid.
A solution so prepared, mixed with a tannin solution, yields a very limpid sea-green writing fluid, and as all the constituents remain in solution, no gum or other suspending medium is necessary.
On long exposure to air, as in inkstands, or otherwise, tannin inks gradually become thick and ropy, depositing a slimy sediment.
Over the mixture is poured lukewarm water, which, percolating down, extracts and carries with it the tannin of the galls.
In the case of Aleppo galls this change takes place by fermentation when the solution of the galls is exposed to the air, the tannin splitting up into gallic acid and sugar.
Amounts of gelatine and tannin in leather of different tonnages, etc.
After treating with air, alcohol is used, which dissolves principally the coloring matters, tannin which has not become assimilated, bodies analogous to resin, and some extractive substances.
The subjoined is a statement of the gelatine and tannin in leather of different tannages, and also shows the amount of azote or elementary matter contained in each: Gelatine.
Percentage of tannin absorbed under different methods of tanning.
The percentage oftannin absorbed by the different methods of tannages appears in the following table: Hemlock 64.
Furthermore, the perceptible proportion of tannin remaining absorbed by a like amount of hide is another powerful argument.
Some think that tannin assimilates itself with the hide and becomes fixed there by reason of a special affinity.
The fact that tannins retard intestinal peristalsis, whereas coffee promotes this digestive action, lends further proof to the non-existence of tannin in coffee.
On the whole, one may say that the small quantities of tannin ordinarily taken with the food and drink are not injurious, but that large quantities (excessive tea drinking) are certainly deleterious.
The chemical analysis of brewed coffee shows the following: Coffee Tannin Comparative per Cup Proportions Percolator method,[379] fine gran.
The tannin of coffee is scarcely astringent, and, therefore, lacks this action," which is proven by the fact that it does not precipitate proteins.
This is effected by first steeping the cotton in a cold solution of tannic acid or in a cold decoction of some tannin matter, e.
I had some tanninplaced on the flap and then covered thickly with gum.
Now if that letter were steamed open the tannin and the sulphate would come together, run, and leave a smudge.
It is used as an infusion internally in the hæmoptysis of consumptives, and externally in the treatment of sore throat, its action being due to the large amount of tannin it contains.
The large proportion of tannin which both species contain in their unripe state, makes them very useful in treating diarrhoea and dysentery.
In decoction they are used for diarrhoea and dysentery, on account, doubtless, of the tannin they contain.
In addition to the oil called cardol, the pericarp contains an especial acid anacardic, a little tannin and ammonia.
The bark is astringent by virtue of the large quantity of tannin it contains.
It is better to give the "tannate of pelletierine," a compound of tannin and one of the alkaloids that Tanret discovered in pomegranate root.
In regard to the mangosteens we must not forget that, while the bark is given because of the amount of tanninit contains, the composition of the pulp is very different.
Kino is at present used but little in therapeutics and its action is analogous to that of tannin and catechu.
It seems quite clear that the tannin is the active principle which is the more probable because its anti-periodic virtues are now recognized by all therapeutists.
The same preparation is used in the Philippines in the treatment of dysentery and diarrhoea and its effect is doubtless due to the large quantity of tannin it contains.
The above list will hopefully give you a few useful examples demonstrating the appropriate usage of "tannin" in a variety of sentences. We hope that you will now be able to make sentences using this word.
