SUBSTITUTION OF ALKALINE BASES. 71 



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 combination with organic 

 acids gives great weight to the opinion that alkaline bases in 

 general are connected with the development 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 extending towards the light, while mere traces of such a 

 substance can be discovered in the roots, herbs, blossoms, or fruits 

 of potatoes grown in fields (Otto). In all the species of the 

 Cinchona, kinic acid is found ; but the quantity of quinina, cin- 

 chonina, and lime contained in them is most variable. From the 

 fixed bases in the products of incineration, however, we may esti- 

 mate pretty accurately the quantity of the peculiar organic bases. 

 A maximum of the first corresponds to a minimum of the latter, 

 as must necessarily be the case if they mutually replace one 

 another according to their equivalents. We know that different 

 kinds of opium contain meconic acid in combination with very 

 different quantities of narcotina, morphia, codeia, &c, the quan- 

 tity of one of these alkaloids diminishing on the increase of the 

 others. Thus the smallest quantity of morphia is accompanied 

 by a maximum of narcotina. Not a trace of meconic acidf can 

 be discovered in many kinds of opium, but there is not on this 



* " We planted," says Wiegmann and Polstorf, " several plants in a 

 flower-pot filled with common earth from the garden, and watered them 

 with a weak solution of chloride of potassium, having previously ascer- 

 tained that the earth contained mere traces of metallic chlorides. Sub- 

 jected to this treatment, the plants flourished very luxuriantly, so much 

 so that they completely covered the flower-pot, stretching far over its 

 sides. We now transplanted them into the open soil, and did not supply 

 them any longer with chloride of potassium ; but, in the following year, 

 they shrunk and died during the period of blossoming. It follows, from 

 the experiments which we have detailed, that both kinds of plants re- 

 quired metallic chlorides for their proper nourishment, but that it is quit* 

 indifferent whether the chlorine be united with sodium or potassium." 

 (Preischrift uber die anorganischen Bestandtheile der Pflanzen.) 



f Robiquet did not obtain a trace of meconate of lime from 309 lb? 

 of opium, whilst in other kinds the quantity was very considerable 

 {Ann. de Chim , liii., p 425) 



