732 



FARMERS'. REGISTER— GEINE. 



is again acted on by water. If this solution is 

 left, to evaporate sjjontaneously, in contact with 

 air, it becomes covered with an insoluble pellicle, 

 and when a certain dcn'ree of concentration has 

 been reached, the liquor becomes turbid. The 

 solution is precipitated by the sails of tin and of 

 lead: after the precipitation, the liquor is without 

 color. According to Korte, the sulphuretted hy- 

 drogen gas precij)itates it also. This extractive 

 matter is contained in the water of many sjiriugs 

 and streams. The water of the springs of Poria 

 in Westrogotha, contains so great a (juantity that 

 it is colored yellow. When the iron contained in 

 this water is oxydized ii-om the air, the extract of 

 mould is precipitated with the oxide of iron, and 

 the water becomes clear. 



Geine. 



This substance has received diderent names. 

 Bracannot has given to it the name of vlniin, lor 

 reafTons which I have exhibited and opposed in a 

 former part of this work. Dobereiner and Spren- 

 gel gave to it the name of acid of humus, because 

 it combines with the earths and alkalis. But for 

 the same reason we might give the name of acid 

 to more than the half oi' all vegetable bodies. 



Gcme does not exist in vegetable earth only; 

 soot contains it also, and according to Bracannot, 

 it is formed when the saw-dust of wood is exposed 

 to the action of caustic potash. It is almost im- 

 possible to obtain geine in a state of purity. One 

 part of the geine which is met with in a natural 

 Btate, is in combination witli bases; but when we 

 attempt to remove these by an acid, the geine 

 combines in part with the excess of acid, and ac- 

 quires itself (in part) the property of reddening 

 vegetable blues. Geine possesses all the proper- 

 ties of apotheme, and it is produced like other 

 apothemes; that is to say, by the action of the air 

 on dissolved extract of mould. In its natural state 

 it does not act chemically, either like the acids or 

 the alkalis, nor does it have any eflect on the color 

 of vegetable blues. It is but slightly soluble in 

 wafer, which it colors of a pale ycliow; is still less 

 soluble in alcohol, and insoluble in ether. Ex- 

 posed to the action of heat it takes fire, burns at 

 first with flame, then without flame like spunk, 

 spreading a peculiar odor, something like that of 

 burning peat. Submitted to dry distillation, it is 

 decomposed, gives half its weight of a charcoal 

 having a metallic lustre, of empyreumatic oil, an 

 acid water containing acetic acid and sometimes 

 ammonia, some carburetted hydrogen, and a little 

 carbonic acid gas. If geine is held suspended in 

 water, through which a current of chlorine is pas- 

 sed, this whitens it, and precipitates a wliite resin- 

 like substance. Iodine is without action on it. 

 If we add an acid to an alkaline solution of geine, 

 the geine Is precipitated. If the whole of the 

 geine is not precipitated, that part which is pre- 

 cipitated retains in combination a small portion of 

 the base, and leaves, wheti it is burnt, a small 

 quantity of alkaline rLshcs. If, on the contrary, 

 an excess of acid is poured into the alkaline solu- 

 tion, the liquor is discolored, and the precipitated 

 geine strongly reddens vegetable blues, a property 

 which cannot be removed' by placing tlie geine on 

 a filter, and pouring water ujjon it." So long as 

 the liquor which passes through the filter cont'ains 

 fi-ee acid, it ist not colored; then it begins to he 

 colored, and finally it dissolves as mncli as two- 



thirds of its weight of the precipitated mass. 

 These acid properties belong in part to the geine, 

 which owes them to tiie action of the alkali, and 

 which may, in this case, be called geic acid; they 

 ought to be in part attributed to a combination oj 

 the ^eine with the precipitated acid. According 

 to Einhoff, it is the latter case which is really pre- 

 sented, and the acid cannot be carriedoff, but with 

 the aid of an alkali. Sprengel, on the other hand, 

 pretends to have li-eed the geine, by prolonged 

 washing, from the muriatic acid which had served 

 to precipitate it: and to make certain the. absence 

 of the muriatic acid, he has mixed the washed 

 geine with a little nitrate of silver. After evapo- 

 ration to dryness, and calcination, the residue, 

 treated by nitric acid, was dissolved, without leav- 

 ing any muriate of silver. But as muriate of 

 silver, like the other salts of silver, is reduced to a 

 metallic state by bodies containing carbon and 

 hydrogen, and carbon itself effects the same 

 change when disengaged along with water, this 

 result proves nothing. In general, in the descrip- 

 tions of geine, they have attributed the properties 

 of that which has been changed by the action of 

 an alkali, to the geine which has not been altered. 

 The geine which reddens vegetable blues, is the 

 same, whatever may have been the acid which 

 served for its precipitation. Its saturated aqueous 

 solution is of a yellowish brown, and the combi- 

 nation is precipitated anew by acids, excepting 

 the carbonic, and the sulphuretted hydrogen. Col- 

 lected upon a filter, it is presented under the form 

 of a gelatinous mass, of a taste slightly acid, as- 

 tringent — and by drying, it contracts strongly, and 

 forms clots of a deep brown, almost black, with a 

 vitreous fracture, and which are not dissolved 

 again in water after being once completely dried. 

 The aqueous solution of the acid geine, is precipi- 

 tated by the salts of lead, of tin, and of iron; but 

 is not disturbed liy gelatine, albumen, starch, gum, 

 tannin, or solution of soap. According to Bracan- 

 not, it is precipitated by a mixture of the solution 

 of gelatine and gallic acid. The dried geine is 

 dissolved with difficulty, and incompletely, in al- 

 cohol. The solution reddens vegetable blues, 

 whilst the part not dissolved is without this power, 

 though it still pi'cserves the property of combining 

 with potash. Geine is destroyed by concentrated 

 acids. The sulphuric acid dissolves it, taking at 

 the same time a black color, carbonizing it, disen- 

 gaging sulphui'ous acid gas, and leaving for resi- 

 due the ordinaiy products which result from the 

 action of this acid. By the addition of sur-oxide 

 (or black oxide) of manganese, carbonic acid gas 

 is disengaged. The nitric acid dissolves and de- 

 composes geine, with a disengagement of nitric 

 oxide gas, and carbonic acid gas. If the solution 

 is evaporated to the consistence of sirop, and then 

 mixed with water, there is precipitated a peculiar 

 bitter substance in powder, and there arc found in 

 the solution, artificial tannin and oxalic acid. 



Geine forms soluble combinations with alkalis. 

 When an excess of geine is used, the caustic al- 

 kalis are so neutralized by this substance, that they 

 lose their peci.liar chemical action and jiroperties. 

 In this respect geine agrees Avith gluten, vegetable 

 albumen, the brown of" indigo, the sugar of liquor- 

 ice, apotheme, and other bodies not acid. During 

 the evaporation, the solution furnishes a black 

 mass, which acquires lustre by complete drying, 

 and splits, and is easily reduced to a powder. It 



