Published “Use of Colloids in Health & Disease” 1919, he was a leading researcher in all things colloidal. From his book we can find many useful insights into what a colloid is and what the effects they can have on the body.
The following are quotes from Alfred B Searle:
What is a Colloid?
“The colloidal state may be defined as a physical condition of matter consisting of at least two parts or phases, one of which is the active substance and the other the one in which it is distributed. The former is termed the disperse phase; it is the active agent and may consist of either solid or liquid particles which are so minute that they remain for an indefinitely long period in suspension. The second phase is either a liquid or an otherwise homogeneous complex material; it is known as the dispersion medium.”
“The dispersed or suspended particles are not merely so minute that the effect of gravity on them is counterbalanced by other forces which keep them in suspension (though they are often only one-thousandth part of the size of average bacteria), but they are in a state of unordered oscillation which gives rise to the well-known Brownian movement.”
Why is it important to have a Colloid?
“Colloidal fluids only retain their characteristic properties so long as their active ingredient is in a properly dispersed and suitable colloidal state.”
“The use of impure and unstable sols is so serious that no pains must be spared in ensuring the purity and stability of the sols used for remedial purposes, and particularly those which are administered by intravenous or intramuscular injection. For these reasons, the remedial colloidal sols prepared by the amateur should not be used until exhaustive tests have proved their efficacy and stability. The author is aware of a number of severe cases of poisoning which were due solely to the use of impure colloids with a very low degree of stability.”
“Some of the most fruitful results in this line of research are those which have followed the discovery by the late Henry Crookes in 1910 that certain metals when in a colloidal state have a highly germicidal action, but are quite harmless to human beings.”
“By converting the metal into the colloidal state it may be applied in a much more concentrated form and with correspondingly better results.”
“Unlike certain organic compounds of silver, the colloidal metal is not organotropic and does not cause necrosis of the underlying tissues. Hence, it has been used for several months consecutively without staining the conjunctiva. Taken internally, the particles of colloidal silver are resistant to the action of dilute acids and alkalies of the stomach, and consequently continue their catalytic action and pass into the intestine unchanged.”
Can anyone make a Colloidal Sol?
“It is most important to observe that it is relatively easy to produce a colloidal sol of low stability and containing a considerable proportion of impurities; it is peculiarly difficult to prepare pure sols which remain stable when mixed with the bloodserum and other physiological fluids.”
“Again, it is comparatively easy to prepare sols which will meet the ordinary requirements of the chemical lecturer, but such crude preparations are usually too unstable for medical purposes, or their stabilising agent or other constituents bring about undesirable complications in the patient. It is, therefore, of the greatest importance that the colloids used by physicians should be prepared with special skill and care.”
What does properly prepared Colloidal Silver sol look like?
“Colloidal silver, containing 0-05 (500ppm) per cent of the metal in a colloidal form and not as a salt, is a clear cherry red liquid which possesses a marked oxidizing action in addition to its power of coagulating colloids of opposite electric sign.”
Stability of the sol is of the utmost importance.
“A quick test – Thus, a colloidal solution of silver gives no precipitate with a solution of a chloride.”
“The stabilising or protecting of a colloidal sol depends on its being in a state of equilibrium between the forces tending to cause these small particles to coalesce (surface tension) and those tending to cause dispersion of the colloid throughout the medium. Stability appears to be due, in most cases, to a union of the particles to be stabilised with those of the protective colloid or with ions which have a stabilizing action.”
“Speaking broadly, pure suspensions of a colloid in water are quite useless physiologically and pathologically, as they are decomposed immediately they enter the blood stream. By preparing them in a suitable manner with the proper stabilising agent in each case, this objection may be completely overcome.”
“Moreover, by virtue of a property well known in physics the particles having a like electric charge tend to repel one another and thus increase the stability of the liquid.”
“When prepared under suitable conditions and properly “protected,” colloidal silver sol is quite stable even in the presence of salts and of the normal constituents of the blood.”
What happened then is happening now.
“From what has already been stated it will be seen that the application of colloidal sols to diseased conditions of the human body is distinctly encouraging, but like all other new ideas it has had its share of drawbacks and discouragements, due in almost every instance to ignorance. Among other causes the premature supply of improperly prepared and unstable colloids has been one of the most serious sources of trouble.”
“There is, in some quarters, an idea that colloidal sols are too unstable to be of real value in pharmacy This is undoubtedly true of the crude preparations made by those who have not the necessary knowledge and skill, but it is emphatically false when applied to the preparations to which reference has already been made.”