60 



HUTCHINSON'S POPULAR BOTANY 







crystals as to render the plants quite brittle. Dr. Carpenter, in his work on 

 the microscope, relates that when some specimens of Cactus senilis, said to 

 be a thousand years old, were sent to Kew Gardens from South America 

 some half -century ago, "it was found necessary for their preservation 

 during transit to pack them in cotton like jewellery," so fragile were they 

 from the quantity of crystallized acid in their tissues. 



Plant crystals are al- 

 ways formed of oxalate 

 of lime or potash. The 

 lime enters the plant as 

 sulphate of lime, and 

 when the sulphur after- 

 wards used by the proto- 

 plasm in the manufac- 

 ture of new proteids 

 (p. 57) has been separ- 

 ated by the protoplasts, 

 the lime combines with 

 the oxalic acid already 

 in the plant, and crystal- 

 lization takes place. 

 The crystallized acid has- 

 much the appearance of 

 Epsom salts, but it is 

 highly poisonous. 



Never speak of the 

 formation of crystals as 

 " growth." This has 

 sometimes been done, 

 even by writers of con- 

 siderable reputation, but 

 it is a mistake. Only 

 living matter can be 

 FIG. 89. MABJOKAM (Origanum vulgar e). truly said to grow ; and 



One of the most fragrant of our herbs, whose masses of purple flowers cover CrVStals are not living; 

 acres of dry chalk-land. It belongs to the family of Labiates, or lipped flowers. J ,. ml 



One- third of natural size. EUROPE, N. AFRICA, N. ASIA. matter. 1 lie prOC6SSeS 



of crystal formation are 



entirely different from the wonderful and all but miraculous life-processes of 

 protoplasm. The first are purely chemical in their nature, and may be success- 

 fully imitated in the laboratory ; the second are vital rather than chemical, and 

 defy imitation. A schoolboy may be taught to make crystals ; the most skil- 

 ful chemist cannot make a grain's- weight of living matter. " The processes 

 are absolutely distinct," says Professor Beale, " and the 'growth' of living 

 things implies Life, and such growth never occurs in the absence of Life." 



., 

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Photo by-] 



IE. Step. 



