or the O- side). Carbon is the pole which lies diametrically opposite to the fixed, stabile elements of the noble gas series (likewise the steadiers of the balance), when one considers the periodic system pictorially as a spiral arrangement on a cylinder surface. The longer the arms of the “balance” through the deposit of new elements on both sides, the more living the play of the balance or to leave the illustration: there develops from the point of departure C that unending series of new configurations, from whence (materially considered!) finally the living from is born, bloms, or whatever word may be used to symbolically designate it since a mechanistic expression is unsuitable. This place of a new addition in the natural structures also signifies for our consideration, the material reciprocal actions with the living man, a new exit and at the same time a crossing. The carbon compounds which we include withe bridge, from the plant and animal medicinal substances.
From group IV only the first two elements carbon, carbonicum, C, and Silicium, Si, are drawn into the circle of our consideration. These two tetravalent amphoteric elements appear in nature as powerful opponents; carbon as the point of departure and pillar of the entire organic world, silicium as the inorganic crust of the solid earth shell down to a depth of 1100 km. If carbon once appears in the oxygen compound CO2 in the circulation of life then it unfolds the infinitely great number of carbon compounds, beyond human comprehension, by virtue of carbon having the capacity of self-combination in series and rings and through the innumerable and easily convertible compounds particularly with H and O. In contrast to the unlimited alterations in shape, the oxygen compound of silicium, SiO2, stands as a rigid inorganic principle.
Thus at first glance the cleft between these two neighbors seems unbridgeable. If however one draws carbon into comparison only in so far as appears in the life of the organism or after its return from the circulation of life into an elementary from, then obviously the chemically inert “coal” (if we employ this embracing name here apart from the various physical structures and the almost constant admixture of other substances) then it is on an even plane with silicium. Both are almost chemically inert. Both come into consideration for reciprocal action with the organism by forces of the same type, surface powers which become effective through physical subdivision, the collodial state. Physical structure differentiates the actions of these charge carrying molecular aggregates more than does the nuclear charge differences of the elements formed.
On this account the medicinal relationship of silicic acid to carbon comes much more distinctly in evidence, the nearer the latter approaches the pure elementary and t the same time mostly inorganic form. Among the common medicinal substances graphites fulfill these presumptions the nearest. Therefore we shall open the carbon series with it after we have first learned silicium in the oxygen compound as a drug.
Silicium in the form of silic acid salts next to oxygen is the most extensive element of the lithosphere, and it is fundamentally the chief constituent of the earth crust. Bunge gives a picture of the struggle of carbonic acid with silicic acid for predominance in the building of the earth crust. Silicium appears as silicates in the plant and animal organisms. It will concern us only in this form or as the anhydride of silicic acid, silicium dioixide, SiO2.
The colloidal nature of pure silicic acid seems to have been known to Paracelsus because he states in the Book “De natura rerum”: “the life of quartz and flint stones is a mucilaginous material”.
APPEARANCE AND SIGNIFICANCE IN PLANTS AND ANIMALS
The content in silicic acid seems to decrease in the series of organisms from the lower plants to the higher animals. In the plants it appears as a supportive substance. It is abundant in alga, equisetum, polygonum, and grasses; in bamboo it is enriched in the so-called sections in the region of the nodes. Even today it plays a great role as a drug in the Orient.
Herbivorus animals are also richly supplied with silicic acid. In sheep and swine formation of silicate stones may occur. Also in animals silicic acid always passes into the supportive substance, it forms the shells in some, and in birds the ashes of the feathers have an especially high content. In man silicic acid appears most strongly in the connective tissues, in the skin and its appendages, nails and hair. The regular total content in the human body however is small, about 0.001 Percent.
That silicic acid appears in the urine (average 0.1 gram per day) suggests an actual silicate metabolism. Moreover it is also excreted through the large bowel after absorption. In the excretion from the large intestine of a man whose natural feces were passed through an artificial fistula in the small intestine the ash amounted to 3.15 Percent determined as SiO2. The loss of SiO2 with skin desquamation, nails and hair, makes some additions necessary.
Even in plants the role of silicic acid is probably not exhausted with the supportive function. As a hydrophile colloid silicic acid can retain water in varying amounts, indeed amounting to multiples of its own weight. It may be remembered that the plants growing on stony soils are able to create a considerable water reserve through this property of silicic acid. The increased absorption from a siliate rich soil also proves a defense against drying.
In the human organism apparently the function of silicic acid is supporting and structure giving, because it is found most abundantly in the particularly resistant tissues. Thus silicic acid in the organism forms a counterpole to the supportive function of calcium which prevails in part in the carbonic acid, the close neighbour of silicic acid.
Silicic anhydride, SiO2 is chemically very inert, being attacked only by the fluoride ion. The essential silicate functions are physical in type. SiO2 is a colloid of complicated structure, is highly molecular, is difficult to break down, and also physically difficult to attack. It is never in true solution but only colloidally dispersed. Actual salts of silicic acid occur only in solid form, and they are peculiarly complex compounds of the metal oxide with SiO2; for example Na2SiO3 is decomposed in water to NaOH and SiO2.
SiO2 is a negative colloid, as most body colloids which however arise from carbon. With this may be associated the extensive independence of silicic acid in contrast to carbon colloids. Through its physical structure and chemical stability silic acid can assert itself in the organism and in contrast to the organic colloids, it is not susceptible to splitting. To a certain extent they are a counterpole of the organic. They are found especially where the chemical metabolism is low or has ceased. Thus silicic acid will be taken up an transported as a foreign body by the phagocytes and will be found for the most part in the hair and nails in solid form, otherwise it is precipitated chiefly in the connective tissue of the body and always where the organic metabolism is at a minimum. One finds the ever present SiO2 in traces in all tissues and excretions; since it is present in dust it can be removed only with difficulty in analysis. The marked silicic acid content of the bronchial glands of millers who inhale much SiO2 with flour dust, shows transportation via the lymphatic ways.
an especial enrichment of silicic acid in the pancreas has been asserted. The pancreas is said to be a site of strong of silicic acid. But from the analysis of these authors themselves, the amount of silicic acid in the pancreas is not greater than that found in other organs. Hugo Schulz has definitely contradicted the above assertion through numerous analysis.
STIMULATION OF FIBROBLASTS
Kobert would conclude from quantitative studies on healthy and tuberculous lungs that silicic acid participates in the healing of tuberculous foci, and that deficient silicic acid prevents healing. But a survey of numerous quantitative studies of French and German authors shows that this deficiency theory is not maintainable. If silicic acid is used in the tuberculous lung, then it is not as a nutritive substance but as an excitor of connective tissue growth. For this the experimental investigations of Kahle and Rossle are of great significance. They found that the administration of silicic acid preparations, 0.5-2.0 g. daily, in experimentally produced tuberculosis of guinea pigs, in and around the tubercle formation a new connective tissue, distinct encapulation and gradual scarring off the tuberculous tissue; it occured entirely in the manner of scaring in tuberculous foci in man. With 0.5g. (per os) the connective tissue of loose fibres, with 2.0 grams in solid fibres. Rossle recognizes in sick guinea pigs even on the 5th day of treatment with silicium a suddenly awakened fibroplastic activity of the tubercle. Likewise after silica acid treatment in experimental animals with tuberculous livers, an actual cirrhosis with new formation of billiary passages develops. New growth is also observed in the tuberculous spleen connective tissue. Outside of Rossle, Gye and Purdy demonstrated a fibrous inflammation of the liver, spleen and kidney with small doses of colloidal silicic acid.