452 MANIPULATION. 



tinually rising up in the middle, and radiating in gentle curves 

 to the circumference. 



" 4. If the liquid be put into a very small phial, similar 

 motions are perceived, the particles when they have reached 

 the side of the phial, going down to rise up afterwards in the 

 centre or axis. 



" 5. If a bubble of air be enclosed in the liquid, motions, 

 similar to those described in No. 2, are observed in the part 

 immediately in contact with the bubble. 



" 6. In a flat drop of new wine laid on the tablet or disc of 

 the aquatic live box, but not compressed by the cover, the 

 motion was a regular uniform circulation, the particles rising 

 from below at one end of the drop, then passing straight across 

 on the surface, and descending at the other end." 



Besides the objects belonging to the animal and vegetable 

 kingdom previously described, there are others which, though 

 mineral in their nature, are nevertheless composed largely of 

 the remains of organized beings ; they may be classed, first, 

 into those that are of animal origin, or contain the remains of 

 animated beings; and, secondly, into those that are entirely 

 of a mineral formation; the former require to be viewed 

 either when in a state of minute division, or when cut into 

 very thin slices, whilst the latter may generally be examined 

 as opaque objects, with a low magnifying power, and without 

 any previous preparation. The sand found largely upon the 

 sea-shore in some parts of the world, and that met with in the 

 interior of shells and sponges, is exceedingly rich in minute 

 foraminifera, and spicules of gorgonia and sponges ; the bins in 

 the shops of merchants who prepare and deal in West Indian 

 and Turkey sponges, will afford a rich harvest to the micro- 

 scopist. The sand from the Caleaire grossiere, of Grignon, 

 near Paris, is exceedingly rich in very beautiful forms; so 

 also Is that from the island of Delos. The shells may be 

 picked out from either of these by the employment of a black 

 card, a sharp-pointed sable pencil, and one of the single micro- 

 scopes represented by figs. 27, 33, and 34; they should be 

 mounted either on black discs or in cells; being of a white 



