FALSE NETWORK BETWEEN GRANULES 209 



minute granules behave which are lying closely packed 

 together in a liquid, or which have been dried up on a 

 slide; that is to say, what appearance they present with 

 high magnifications. 



If some Chinese ink, rubbed up into rather a thick 

 paste, or else some sepia of the same consistency, which has 

 been removed from the ink sac, be spread out on a cover-slip 

 in a thin layer and allowed to dry, and then a cover-slip 

 placed over it with damar, the thin layer of ink or sepia, 

 when studied with the highest powers, looks as follows. 

 A very finely meshed but distinct network is to be seen, the 

 nodal points of which seem to be formed by the x very 

 smallest particles of ink or sepia (Photogr. VII.)! It 

 is evident that the phenomenon does not depend on the 

 soluble matter of the ink having been dried up with it, and 

 having formed the reticular tracts between the ink granules, 

 from the fact that it is possible, after drawing the cover-slip 

 with the ink on it through a flame several times, to treat 

 it for a long time with water, concentrated hydrochloric acid, 

 caustic soda, alcohol, and ether, etc., without the appearances 

 being changed. Moreover, the ink or sepia when suspended 

 in water also shows the reticular appearance distinctly, 

 provided it is not, as usually is the case, in a state of violent 

 molecular movement. If one investigates the ink rubbed 

 up with water under the cover glass, it can be observed that 

 wherever a bubble of air is shut in between the slide and 

 the cover glass, a very thin layer of ink is found between 

 the air and the cover glass. In this thin layer of fluid no 

 molecular movement takes place, and there one can see very 

 plainly that the ink granules show reticular connections. 



Just the same appearances are also obtained by slightly 

 blackening a cover glass over a flame and mounting It in 

 damar. 



By these experiments it is shown that closely apposed, 

 and very minute granules also present the appearance of, a ' 

 network. That the granules of the thin dried-up layer of ink 

 are closely packed, however, follows from the fact, that after 

 treatment with acids, etc., the layer frequently comes away 

 partly as a continuous membrane. On what, then, does the 



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