On the Paramecium aurelia. 71 
broken and the contents pouring out, they continue their motion 
with unabated vigor, differing in this respect from those of the 
mouth. . 5 
When a number of these animalcules are dried on a plate of 
thin glass and afterwards heated to redness, an inorganic residue 
temaits corresponding to each individual. This residue although 
not differing materially in shape from the original, yet has = 2 
been so much shrunk that it is not more than one-fourth 
of its size. On treating it with hydrochloric acid it is 
Di 
0 passing a feeble galvanic current through water containing 
these animalcules, on the circuit being completed, a streak o 
organic matter begins to form between the poles, but nearer the 
hegative ; animalcules in the neighborhood and those touching 
move no more. Examined with a high 
power, neither mouth nor body cilia are 
seen to be in action; the body may be ob- 
aay those which approach near the poles, 
Cischarging their entire contents; these Ee. 
duced, but in no case could it have been larger than ;3,th of an 
Inch, even after the lapse of several minutes. 
0 the application of different reagents these effects followed : 
alcohol soon caused the action of the mouth to cease which was 
shortly followed by the cessation of the action of the body cilia 
—deat of course ensuing; often the soft contents contracted 
leaving a portion of the integument unoccupied. Phosphate of 
Soda caused death in a few minutes; sulphate of magnesia, chlo- 
o ammonium, acetate of lead, and perchlorid of mercury 
Catlsed death immediately. Cyanid of potassium the same, 
attended by instant rupture of membrane and violent discharge 
of Contents. When a quantity of oxalate of ammonia is added 
0 the water in which they are swimming, its immediate effect is 
‘0 stupefy ; the action of the mouth and of the cilia cease and 
