72 Chronicles of Science. [Jan., 
darker shadow pass on to the planet’s disc. The first, when in the 
middle of the disc, was almost as dark as the second when near the 
edge of the limb, but somewhat less in size, “From which it is 
very plain,” he adds, “that the first of these spots was the fourth 
satellite itself, and the second its shadow. We have seen the first 
and second satellites appearing, not as dark spots, but as bright 
ones (somewhat differing from the light of Jupiter), for some little 
time after they have entered the disc; but as they approach the 
middle we lose sight of them; and we have frequently observed 
that the same satellites appeared brighter at some times than at 
others; and that when one of them hath shined with its utmost 
splendour, the light of another hath been considerably diminished. 
From whence it is very probable, at least, not only that the satel- 
lites revolve upon their proper axis, but also that some parts of their 
surfaces do very faintly—if at ali—refiect the solar rays to us,” an 
interesting passage, considering the date of the observation. 
4. BOTANY AND VEGETABLE PHYSIOLOGY. 
AmericA.—Vibrios in Hot-water. Dr. Jeffries Wyman has been 
making some experiments on the appearance in hot-water of living 
organisms, which have some interest as touching upon spontaneous 
generation and some problems of Cryptogamic Botany. He con- 
cludes— 
1. In thermal waters, plants belonging to the lower kinds of 
alge live in water, the temperature of which, in some instances, 
rises as high as 208° F. 
2. Solutions of organic matter boiled for twenty-five minutes, 
and exposed only to air which had passed through iron tubes heated 
to redness, became the seat of infusorial life. 
3. Similar solutions contained in flasks hermetically sealed, and 
then immersed in boiling water for periods varying from a few 
minutes to four hours, also became the seat of infusorial life. -The 
infusoria were chiefly Vibrios, Bacteriums, and Monads. 
4. No ciliated infusoria, unless Monads are such, appeared in 
the experiments referred to in the above conclusions. 
5. No infusoria of any kind appeared if the boiling was pro- 
longed beyond a period of five hours. 
6. Infusoria having the faculty of locomotion, lost this when 
exposed in water to a temperature of from 120° to 134° F. 
7. If Vibrios, Bacteriums, and Monads are added to a clear and 
limpid organic solution, this becomes turbid from their multiplica- 
tion in from one to two days. If, however, they have been previ- 
