The matters which color flowers are uncrystallized; they frequently change by the action of the reagents employed for their preparation; and, also, very brilliantly-colored flowers owe their color to very small quantities of coloring matter.
The second employs reagentsin a dry state, and the action of which requires lamp and furnace heat.
The reagents are solution of mercury iodo-chloride prepared by dissolving of 25 grms.
What reagents are used to discover the presence of foreign substances in nitre?
The samereagents may be used in the examination of gunpowder, as we shall notice hereafter.
In the more exact investigations of the tissues, it is often necessary to have recourse to other reagents than those we have used hitherto, in order to bring out plainly the more obscure points of structure.
In addition to these implements, a few reagents may be recommended for the simpler histological work.
And we have no more right to call cells granular in which proteid precipitates occur, either spontaneously as in coagulation, or from reagents (alcohol).
For the ordinary staining reagents (in watery fluids) it is enough to place the air-dried preparation at about 110° C.
Fischer's publication, where the formation of granule-like precipitates under the influence of various reagents is experimentally demonstrated, grave doubts as to the reality of Altmann's forms have been raised from various quarters.
Doubtless, just in the same manner as we now (by means of well-known reagents which are common in nature) precipitate it in the laboratory.
These reagents will attack the bisilicates and felspars.
Why the junction of lodes is often found to be more richly metalliferous than neighbouring parts is probably because there the depositing reagents met.
With the use of other condensing reagents the procedure may be as in the process of the B.
When reagents are removed from bottles, the stopper should be held between the first and second fingers of the right hand (see Fig.
From time to time processes are published under “queer” names, which are based on the well known actions of reagents on the ferric salts reduced by light.
The carbon proofs can be toned and at the same time intensified by reagents acting with chromic oxide.
He pronounced the opinion that it was some alkaloid, for such it was shown by the reagents he had used in his analysis, but of what nature he was utterly at a loss to determine.
Yet from the result of certain group reagents it would appear that death was due to the virulence of some azotic substance.
He is a test-tube; such and such reagents are needed to produce a certain result, and there you are.
The great pathologists of that time had not the lenses, microtomes, andreagents that are now in daily employment; they knew nothing of the present methods of section-cutting and differential staining.
Aluminum is used principally in castings and drawn and pressed ware, for purposes in which lightness, malleability, and unalterability under ordinary chemical reagents are desired.
Molybdenum chemicals are essential reagents in iron and steel analysis and other analytical work; they are also used as pigments.
With the general reagents for alkaloids brucia gives precipitates.
The tests for arsenic are almost inconveniently delicate, so that the slightest impurity of the reagents will make it appear to be present.
Hydrocyanic acid is not formed during putrefaction, nor by heating organic substances with chemical reagents at temperatures up to 212° F.
The purity of the various materials and reagents employed in this investigation was most scrupulously ascertained.
All the generalreagents for alkaloids precipitate strychnia.
In order to avoid repetition, the mode of preparing the general reagents for alkaloids will be given here.
The bleaching effect of none of these reagents is permanent, especially when the product is exposed to the air and light.
Before considering the methods to pursue and the reagents to use, it is well to decide first upon the grade of sugar it is desirable to make.
There is a great variety of reagents at the command of the sugar manufacturer, each of which has certain merits over others, and all are valuable in their place when properly used.
It is the purpose of this article to give a brief survey of the more common reagents which, under certain conditions, may be used to advantage in these Islands.
While ordinary clarifying agents help to a great extent, if the melted sugars are very dark from caramel and the decomposition products of calcium glucosate, these reagents can not be expected to give a light-colored juice.
The aqueous solution precipitates gelatine and aniline hydrochloride; all other tannin reagents give no reaction.
Reagents suitable for Demonstrating the Various Stages of Neradol D Tannage 8.
These reagents precipitate colchicine, but do not affect solutions of digitaline or picrotoxine.
The purity of the reagents used having thus been confirmed, the clamp d is closed until the acid is forced back into f; and the materials to be examined are then added to the fluid.
It is, however, often necessary to apply the above reagents several times before the original writing becomes apparent; indeed, in some cases months have elapsed before the reaction has occurred.
The presence of silica does not interfere, it being insoluble in the reagents commonly made use of.
When the precipitate is to be dissolved in reagents that do not affect the paper, such as ammonia, tartrate of ammonia, and dilute acids, it can be brought in solution directly on the filter.
The absolute purity of reagents is not always to be attained, and the results of an analysis are the more certain, in proportion as they are less numerous and more easily purified.
In cases, however, wherereagents which attack the paper are employed, the precipitate should be separated.
With somereagents the full effect takes place almost instantaneously, while with others the effect takes place slowly.
In studying the effect of chemical reagents in plants, the method is precisely similar to that employed with nerve; that is to say, where vapour of chloroform is used, it is blown into the plant chamber.
In the method of negative variation, one contact being injured, the chemical reagents act on injured and uninjured unequally, and it is conceivable that by this unequal action the resting difference of potential may be altered.
XVI study in detail the effect of chemical reagents in producing the enhancement or depression of excitability.
This difficulty as regards the obtaining of response was overcome in the method of negative variation, where the excitability of one end was depressed by chemical reagents or injury, or abolished by excessive temperature.
The reagents were applied in the form of a solution on the tissue at the two leading contacts, and the contiguous surface.
My second misgiving was as to whether the action of reagentswould be sufficiently rapid to display itself within the time limit of a photographic record.
The effect of these reagents is not only to increase or diminish the height of the response-curve, but also to modify the time relations.
But by the block method the two contacts are made with uninjured surfaces, and the effect of reagents on both is similar.
We may thus by reducing or abolishing the excitability of one end by means of suitable chemical reagents (so-called method of injury) obtain response in metals without a block.
It would appear as if the reagents which act as poisons produced some kind of molecular arrest.
The earliest inks that were rendered visible by chemical reagents were believed to act by magnetism.
It is useful to submit to the same reagents simultaneously portions of cloth dyed in a known manner with the wares which are suspected of having been used in dyeing the goods under examination.
In each case, a group name and the characteristic reagentsused in separating a group from those following it, are given.
Hydrogen sulphide is used, in this way, as one of the most valuable reagents in analytical work, enabling the analyst to separate whole groups of metal ions from other groups.
Now, in two of the reagents used, potassium ferro- and ferricyanide, iron is present according to the formulæ given.
The depth of color indicates the comparative amount of indican if the same proportions of urine and reagents are always used.
The reagents are: (1) Saturated solution sulphanilic acid in 5 per cent.
To make sure that the reagents are arsenic-free, the paper cap may be applied for a few minutes before the urine is added.
The above list will hopefully give you a few useful examples demonstrating the appropriate usage of "reagents" in a variety of sentences. We hope that you will now be able to make sentences using this word.
