ACIDS. 



ACIDS. 



that if these do not exist in sufficient quantity j 

 in the soil, other bases must supply their place ; 

 and that the progress of a plant must be wholly 

 arrested when none are present. 



" Seeds of the Sulnola Kali, when sown in ' 

 common garden soil, produce a plant contain- 

 ing both potash and soda; while the plants 

 grown from the seeds of this contain only salts 

 of potash, with mere traces of muriate of soda. 

 (Cadet.') 



"The existence of vegetable alkalies in com- 1 

 bination with organic acids gives great weight 

 to the opinion, that alkaline bases in general 

 are connected with the developement of plants. 



" If potatoes are grown where they are not 

 supplied with earth, the magazine of inorganic 

 bases, (in cellars for example,) a true alkali, 

 called Solanin, of very poisonous nature, is 

 formed in the sprouts which extend towards 

 the light, while not the smallest trace of such 

 a substance can be discovered in the roots, 

 herbs, blossoms, or fruits of potatoes grown in 

 fields. (Otto.) 



" When roots find their more appropriate 

 base in sufficient quantity, they will take up 

 less of another." (LiebitS* Organic Chem.}} 



Vegetable acids abound in most plants ; thus, 

 the Acetic acid (vinegar) -is found in the chick 

 pea (Cicer arietinum), in the elderberry (&im- 

 bums nigra), in the date palm tree (Phcenix 

 dacfylifera), and in numerous others. 



The Oxalic acid is found combined with 

 potash in the Oxalis Acetoselta, or wood-sorrel 

 (whence its name), and many other plants ; 

 united with lime, it is detected in the root of 

 the rhubarb, in parsley, fennel, soapwort, 

 squills, &c.; and in an uncombined state in 

 the liquid which exudes from the Cicer aridi- 

 num, [chickpea, or Spanish Garbanza.] 



Tartaric Acid [or Cremor tartar] is com- 

 monly procured from tartar or tartrate of pot- 

 ash (whence its name). It has been detected 

 in many plants, such as in grapes, tamarinds, 

 bilberries, white mulberries, the Scotch fir, 

 couch grass, dandelion, &c. &c. 



Citric Acid has been found in oranges and 

 lemons, cranberries, red whortleberry, bird- 

 cherry, woody nightshade, the hip, and the 

 onion. 



Malic Acid is the only acid existing in the 

 apple, [pear,] barberry, plum, sloe, elder, ser- 

 vice, &c. It is found with the citric acid in 

 the gooseberry, currant, bleaberry, cherry, 

 strawberry, raspberry, &c. ; combined with 

 lime, it is found in the house-leek, wakerobin, 

 <5cc. ; and with potash and lime, in rue, garden 

 purslane, madder, spinach, lilac, mignionette, 

 &c. 



Benzoic Acid. This acid is found in ben- 

 zoin, balsam of Tolu, storax, &c. ; and in 

 marjoram, clary, chickpea, Tonkin bean, &c. 



The Prussic, or Hydrocyanic Acid, exists in 

 laurel leaves, peach blossoms, bitter almonds, 

 flowers of the sloe, leaves of the bay-leaved 

 willow, &c. : there is little doubt but that all the 

 bitter almond kernels contain this acid. 



Gallic Acid abounds in the barks of many 

 plants, such as the elm, oak, chestnut, beech, 

 willow, elder, plum tree, sycamore, birch, 

 cherry tree, sallow, mountain ash, poplar, 

 hazel, common ash, sumach, &c. 



These are the chief vegetable acids. There 

 are others' which have been detected occa- 

 sionally ; such as the moroxylic, in the Moms 

 alba, or white mulberry; the boletic, in the 

 Boletus pseudo-igniarius , [a species of mush- 

 room,] the meconic, in opium ; the kinic, in 

 the bark of the Cinchona ojfficinalis ,- the cam- 

 phoric from camphor ; the suberic from cork, 

 &c. ; but none of these are of that importance 

 to the cultivator to require a particular notice 

 in this place. The composition of the princi- 

 pal vegetable acids is much more similar than 

 the intelligent farmer might be inclined to 

 suspect, as will be readily seen from a com- 

 parison of the following table of their composi- 

 tion, chiefly by M. Berzelius : 



Acetic acid 

 Oxalic acid 

 Tartaric acid 

 Citric acid 

 Benzoic acid 

 Gallic acid 



Hydrogen 



6-35 

 . 0-214 

 3951 

 3-800 

 . 5'iti 

 . 5-00 



Carbon. 

 4683 



36-167 

 41-369 

 74-41 

 56-64 383 



(Thomson's Chern.) 



Oxv?en. 



4682 



66534 



59-6W2 



54-831 



2043 



[The organic acids of animal origin are, like 

 those obtained from vegetables, very numerous. 

 As examples, there are, the formic acids, first 

 obtained from ants, but now ascertained to 

 exist in sugar and some other vegetable sub- 

 stances : Lactic acid, obtained from milk; 

 Uric acid, procured from human urine, and 

 Hippuric acid, from the urine of the horse and 

 other animals when stall-fed : Margaric and 

 Siearic acids from fat, etc. The Phosphoric 

 acid, though found combined with minerals, is 

 very abundant in the animal system, being 

 combined with lime to form the bones, and ex- 

 isting in the urine and other fluids and solids, 

 in union with alkaline bases, forming phos- 

 phates of soda, potash, lime, and magnesia. 



Phosphoric acid has also been found in all 

 plants, the ashes of which have been examined 

 by chemists, always, however, in combination 

 with potash, soda, magnesia, or lime. Most 

 seeds contain certain quantities of the phos- 

 phates formed by the union of phosphoric acid 

 with some one or more of the alkalies just 

 named. In the seeds of different kinds of grain, 

 there is abundance of phosphate of magnesia. 



Phosphoric acid, in one or other of its com- 

 binations, plays indeed an important part in 

 agriculture, and is an indispensable constituent 

 of all good land. 



" The soil in which plants grow furnishes 

 them with phosphoric acid, and they in turn 

 yield it to animals, to be used in the formation 

 of their bones, and of those constituents of the 

 brain which contain phosphorus. Much more 

 phosphorus is thus afforded to the body than it 

 requires, when flesh, bread, fruit, and husks 

 of grain are used for food, and this excess in 

 them is eliminated in the urine and the solid 

 excrements. We may form an idea of the 

 quantity of phosphate of magnesia contained 

 in grain, when we consider that the concre- 

 tions in the coecum of horses consist of phos- 

 phate of magnesia and ammonia, which must 

 have been obtained from the hay and oats con- 

 sumed as food. Twenty-nine of these stones 

 were taken after death from the rectum of a 

 horse belonging to a miller in Eberstadt, the 

 total weight of which amounted to 3 Ibs. ; and 



23 



