ISDEX. 271 



Dextrine, production of in plants, i. 421 



Dialysis, as a method of separating and analysing substances, i. 108 



what constitutes dialysis, i. 110 



Prof. Graham's instrument for, i. 110 



an extraordinary result of, i. 110 

 Diamagnetism, i. 75 

 Diamond, i. 13, 15 



heat required to consume the, i. 15 



crystallisation of the, i. 15 



its resistance to electricity, i. 90 

 Dianthine, production of, i. 127 

 Diastase, production of, in plants, i. 420 

 Diatoma vulgare, structure and development of, i. 197 

 Diatomaceae, or Brittleworts, found all over the globe, i. 196, 20i 



variety of forms of, i. 196 



structure of, i. 197 



development of, i. 200 



social plants, i. 205 



food for many aquatic animals, i. 205 



fossil deposits of shells of, i. 206 



enormous geological changes caused by, i. 206 

 Dicksonia antarctica, structure of, i. 349 

 Dicksonia lanata, structure of, i. 349 

 Dicksonia squamosa, habitat of, i. 349 

 Dicksonieae, i. 349 



structure of, i. 350 



Dicotyledonous, or exogenous, plants, structure and mode of reproduc- 

 tion of, i. 404-428 

 Dicranei, structure of, i. 329 



Dictyopodium trilobum, structure and habitat of, ii. 20 

 Dictyota, structure of the genus, i. 246 



Dictyota dichotoma, structure and mode of reproduction of, i. 247 

 Dictyoteae, structure and mode of reproduction of, i. 246 

 Dictyurus purpurascens, structure of, i. 242 

 Difflugia, structure and minuteness of the shells of, ii. 22 



their architecture, ii. 23 

 Difflugia pyriformis, structure, and habitat, and mode of propagation of, 



ii. 22, 23 

 Diffusibility, most substances differ in, i. 109 



partial decomposition of definite chemical compounds by, i. 109 



reciprocal diffusion of gases through porous plates, i. 111-113 



the diffusing instrument used by Prof. Graham, i. 112 



