14 ALPINE FLOWERS [PART I. 



of granite. The vegetation that adorns them is directly subject to 

 their influence, and hence becomes a flora either calcareous or 

 silicious. Thus, also, there is among the alpine plants that we have 

 in cultivation, some that desire or actually require lime, just as 

 there are others that avoid it, and must have silica. It is important 

 to know to which category the various plants belong, in order to 

 combine them rightly. There are, notwithstanding, a great number 

 indeed the larger number of mountain plants whose distribution 

 is general, and which do equally well in either soil. ^ It is just these, 

 of all the plants of the Alps, that submit most readily to cultivation, 

 and that have long been established in gardens. 



But there are great numbers of other species which, though easy 

 to grow at Geneva, where the soil, the water, and the stone contain 

 lime, are by no means so accommodating in the west of France or in 

 the parts of England that are granitic ; while there is a whole range 

 of other species that are readily grown in these regions, and that 

 we cannot persuade to feel at home in our lime-impregnated 

 garden. 



One of my friends, Dr A. Rosenstiehl, a chemist, who is also an 

 excellent botanist, has gone deep into the subject, and, thanks to a 

 system of watering with distilled water, has arrived at some excel- 

 lent results. He set to work with all the necessary care and pre- 

 caution, keeping his granite rock free from contact with lime, and 

 the results he has obtained prove that those botanists are right who 

 class some plants as lovers, and others as haters, of lime, and others 

 again as inimical to granite. 



The juices of plants are acid ; these acids, when brought into 

 contact with the carbonate of lime absorbed by the plant, become 

 saturated and neutralised. There are formed therefore in the plant 

 certain salts of lime, which, if they are soluble in water, can circulate 

 in its organism ; but if they are insoluble, as is often the case, the 

 channels of circulation become choked, and nutrition is impeded. 

 Their presence, therefore, is a mechanical impediment to the well- 

 being of the plant. Dr Rosenstiehl has verified the presence of 

 such acids in the lime-hating plants he has examined, and it is 

 certain that these plants, if grown in soil containing lime, will 

 sooner or later become poisoned. He has shown me in his garden 

 examples of Sphagnum and Vaccinium, plants essentially lime- 

 hating and granite-loving, whose leaves were throwing out small 

 calcareous crystals and were dying. All plants, however, require 

 lime in a certain proportion for the building up of their tissues, and 

 it is found in the ashes of even the most lime-hating of plants. 

 Each species must have a certain amount, but cannot endure too 

 strong a dose, and on these a little too much acts as poison. The 

 careful cultivator must therefore learn exactly how much must be 

 given to each species. 



Dr Rosenstiehl grows Asplenium germanicum in soil containing 



