A rapid method of separating colloids from crystalloids in solutions containing both/ 59 J.
The colloidsshow an infinite diversity of variations in these essential properties: certain of them, and notably cellulose (q.
The animal fibres are composed of nitrogenous colloids of which the typical representatives are the albumens, fibrines and gelatines.
Of particular interest to physicians is the chapter on “Administration of Colloids in Disease” written by Alfred B.
The Council has reported that a number of the “Collosol” preparations were notcolloids at all, and “if .
That removal of colloids and resins materially affects the tolerance of these drugs is improbable.
The “scientific” evidence presented by Searle for colloids in medicine reads as if the advertising literature of the Crookes concern had been considered ample source of information.
Such indeed they proved to be, since the deductions drawn from the behaviour of colloids and from Leduc's pretty toys were promptly disclaimed by leading chemists in the course of the few days after the delivery of the address.
When colloids separate out from solutions, or from a molten state, they present a form which is similar to that of the liquid from which they were formed.
One of the properties which distinguish colloids from crystalloids is that the former pass very slowly through a membrane, whilst the latter penetrate very rapidly.
Graham and others observed the power shown by colloids (see note 18) of forming similar hydrosols or solutions of gelatinous colloids, and, in describing alumina and silica, we shall again have occasion to speak of such solutions.
The entire series of colloids on separating from water form similar compounds with it, which have the aspect of solid gelatinous substances.
Colloids are distinguishable from crystalloids, not only by the absence of crystalline form, but by many other properties which admit of clearly distinguishing both these classes of solids, as Graham showed.
On breaking solid colloids into pieces, a total absence of cleavage is remarked.
Nearly all colloids are capable of passing, under certain circumstances, from a soluble into an insoluble state.
In this connection we must not lose sight of the researches made by Ord[157] on the action exerted by colloids on the formation of concretions.
Footnote 157: On the Influence of Colloidsupon Crystalline Forms and Cohesion, with Observations on the Structure and Mode of Formation of Urinary and other Calculi, by W.
This property of colloids enabled Mr. Graham to account for a number of special results of observation, not previously explained.
They may be adsorbed like other colloids by "shaking out" with finely divided suspensions like charcoal or kaolin, or by other colloids like aluminum hydroxide or proteins.
Coddle the Colloids With phosphorus, iron and Beans; Though Mineral Salts may have some faults, Bring on the Vitamines.
Living beings are but solutions of colloids and crystalloids, and their tissues are built up by the aggregation of these solutes.
Colloids diffused in water are usually called colloidal solutions, but they are not true solutions.
We say that colloids have no osmotic pressure, whereas in fact the osmotic pressure of the colloids though feeble plays a very important part in the phenomena of life.
Until recently it was generally believed that diffusion took place in colloids and plasmas just as in pure water.
In some cases it is a reversible phenomenon, thus gelatine coagulated by cold is redissolved by heat; whereas with other colloids the process is irreversible, albumin coagulated by heat is not redissolved on cooling.
Many colloidssuch as haemoglobin are crystallizable, and many crystallizable substances are coagulable.
After death the colloids which have constituted the form of the living thing pass from their liquid state as "sols" into their coagulated state as "gels.
Colloids differ from crystalloids in that they do not form crystals from solution, being completely amorphous when in the solid state.
Colloids in a state of coagulation have a vacuolar or sponge-like structure.
Bredig has studied the catalytic decomposition of hydrogen peroxide by metallic colloids prepared by his electric method.
In the properties ofcolloids and crystalloids Graham saw an index of diversity of molecular structure.
He proved that a colloidal substance acts towards a crystalloid much as water does; that the crystalloid rapidly diffuses through the colloid, but that colloids are not themselves capable of diffusing through other colloids.
He at first thought that crystalloids are always inorganic compounds, while colloids are of organic origin.
Finally, colloids mutually adsorb each other, as in the case of the "protective colloids" previously referred to.
Bodies in the first state he called crystalloids; those in the last state, colloids (resembling glue).
He also showed that, in accordance with the general chemical rule, while colloids readily combine with crystalloids, bodies in the same condition manifest little or no tendency to chemical union.
These colloids appear to be separated by amyl alcohol in virtue of their greater solubility in that menstruum.
By distillation, these colloidsappear to be destroyed or changed so as to allow the paraffine to crystallize.
He brings together many facts to support the view that in the living tissues impaired circulation, and especially diminished oxidation, are the chief causes of increased affinity of the colloids for water.
The relation of osmosis, lymphagogue activity, absorption of edema, capillary contractility and decreased affinity of ocular colloids for water to the reduction of increased intra-ocular tension.
Very interesting are the observations on the subconjunctival injections of various substances, notably the citrate of sodium, because of its power of decreasing the affinity of ocular colloids for water.
The affinity of the tissues for water, or, as Fischer explains it, the affinity of the tissue colloids for water, seems too little related to the requirements of ocular function to furnish the needed regulation of tension.
Fischer has shown, that when the enucleated eyeball is placed in a weak solution of hydrochloric acid, the swelling of the tissue colloids is sufficient in a few hours, to burst the sclero-corneal coat.
Reduction of ocular tension by stimulation of osmosis, of lymphagog activity, of absorption of edema, and of capillary contractility, and by decreasing affinity of ocular colloids for water.
Colloids that are undergoing decomposition are also specially powerful, so that the presence of bacteria or fungi causing fermentation is an important factor.
The salts that are deposited by mere chemical reaction without the intervention of colloids appear in the form of sharply defined angular crystals, and hence the rough, jagged crystals of oxalate of lime or ammonia-magnesium phosphate.
Heat intensifies the action of the colloids in causing precipitation of the dissolved salts, so that the temperatures of the kidneys and bladder constitute favorable conditions.
Naturally the subjects of ultramicroscopy and protective colloids are discussed in detail--the author originated the "gold figure" used to express the protective effect of a colloid.
All life processes take place in a colloid system, and the necessity to physiologists of the study of colloids is forcibly emphasised.
Precipitation is complete only when the colloids are used in the proportions required to neutralize each other's charges [Billitzer, ‹Z.
Precipitation of Colloids by Electrolytes and by Colloids.
Colloids which do not carry any electric charges of moment (see p.
This is probably true of all amphoteric colloids (Chapter X); it is also true of many other substances, which are not pronouncedly amphoteric.
From the fact that colloids are unable to traverse membranes, through which crystalloids readily pass, Graham had reached the same conclusion.
In this condition the colloids (gold and stannic acid) are sensitive to precipitating electrolytes, and the solution is more sensitive to a mixture of magnesium nitrate and ammonium nitrate than to ammonium nitrate alone (‹exp.
On the other hand, the colloidsof one important group are found to be almost without any electric charges;[260] the passage of an electric current through their suspensions has little or no effect on them.
Profiting by their experience, they turned to the colloids in hope of a clue.
Broadly speaking, the lyophile colloidscorrespond to the emulsoids, and the lyophobe colloids to the suspensoids.
The fundamental idea of modern colloid chemistry is that colloids are heterogeneous systems, usually two-phased, in which one phase is liquid and the other phase either liquid or solid.
Tannins, on the other hand, are hydrophile colloidswhich in water form emulsoid sols, and which may thus be expected to exhibit the phenomenon of adsorption.
The crystalloids and semi-colloids may also be obtained in colloidal solution, sometimes being so changed on the mere addition of salts to the solution.
The drift of his work had been to identify all colloids as liquid solutions of variable degrees of viscosity, and to treat crystalline bodies as the only solids.
Ries (6) has, in fact, pointed out that colloids alone lack cohesiveness and solidity, and a fine mineral aggregate is necessary to change them into a plastic mass resembling clay.
This water may be removed by drying, only to be re-absorbed on cooling, but if the heating temperature is excessive the structure of the colloids is destroyed.
The above list will hopefully give you a few useful examples demonstrating the appropriate usage of "colloids" in a variety of sentences. We hope that you will now be able to make sentences using this word.
