OKI 



Swedish filtering paper, and boiling for half an hour or more 

 in no way destroyed their vitality.^ 



Not merely does Dr. Bastian believe that from the re- 

 arrangements of the particles of various saline substances in 

 solution living beings may de novo originate ; but he also states 

 that this may actually take place within crystals of such com- 

 pounds. He gives the details of his observations in these, 

 as in other cases, with a minuteness which is most con- 

 scientious, especially as it is often hardly possible to avoid 

 thinking that they suggest quite a different explanation. 

 Crystals of ammonium tartrate were found after being kept 

 some time to have undergone certain changes, the external 

 portions became more or less opaque, and less soluble, and 

 gradually increasing bubbles are seen in internal cavities, 

 especially in those crystals which are not perfect in shape, 

 and which present a more or less opaque appearance in their 

 interior." It is by no means improbable that a crystal pre- 

 senting these characters is not homogeneous throughout, and 

 a porosity of the interior, which would explain the opacity, 

 would be likely to be increased by the unequal effects upon 

 a crystal so constituted of changes of temperature. Some 

 of the crystalline layers of agates are pervious to the colour- 

 ing liquids, which are used to stain them ; and these " air 

 bubbles " might be in actual communication with the ex- 

 terior, although they vrould be retained during solution by 

 mere adhesion, and would be finally disengaged with all the 

 appearance of being liberated from closed cavities. The 

 existence of these cavities is, however, rather adduced as 

 an evidence of changes which have taken place in the 

 crystals, and which are the result of the development in 

 them of the organic structures, found to be liberated by 

 solution from their very centres. Granting that the develop- 

 ment actually takes place, it might have been supposed that 

 the centre of the crystal would have been its least likely 

 seat, as being the part least subject to external influences, 

 and therefore with less determining causes for the necessary 

 re-arrangement of its constituent molecules. Another ex- 

 planation seems more probable; the presence of foreign 

 bodies, or " nuclei," in a solution at the point of crystalliza- 

 tion, when adhesion and cohesion are nearly balanced, 

 often, by making the cohesion preponderate, determines the 

 formation of crystals about them. The character of the 

 bodies which were liberated is not incompatible with this, 



» 'Nature,' vol. ii, p. 179. 



L ■Ammonium tartrate is known to effloresce wlicn kept, from the loss 

 of ammonia. 



