1878.] 
Notices of Books. 
103 
years. Then, however, two wet years occurred together (1848 
and 1849), followed by two dry ones, since which Tasmania has 
had an uncertain rainfall. 
A triennial period was suggested by a Mr. Tebbutt, from ob- 
servations taken at Windsor, in New South Wales, and it has 
been also traced to the climate of Ceylon. The author does not 
consider the evidence in favour of an eleven years’ cycle — corre- 
sponding with the supposed period of the solar spots — to be at 
all conclusive. There is, at least as far as Australia is con- 
cerned, much to be said in favour of a nineteen years’ period. 
The author further draws attention to the influence of cosmical 
causes in modifying the climatic conditions of our earth. Thus 
the earth may, and probably does, pass through regions of un- 
equal meteoric density, the heating power of the sun being thus 
temporarily diminished or increased. The fall of temperature 
in February and May, and its increase in August and November, 
producing in the latter month the phenomenon known as the 
“ Indian summer” in America, and as “ St. Martin’s summer” 
in Europe, are instances in point. 
The Rev. W. B. Clarke contributes a valuable paper on the 
“Effedts of Forest Vegetation on Climate, ’’and shows clearly, from 
a mass of evidence collected with great patience and judgment, 
that to denude a country is to destroy its fertility, to expose it to 
the destructive alternation of flood and drought, and to injure 
severely its sanitary condition. 
We regret to find that the Zoological and Botanical Sedtion 
of the Society held no meetings during the year. Surely 
there is an almost unlimited amount of work awaiting its 
attention. 
Transactions and Proceedings of the Royal Society of Victoria . 
Vol. xii. Melbourne : Stilwell and Knight. 
This volume contains no small amount of interesting matter. 
The important question “ Is the Eucalyptus a fever-destroying 
tree?” is discussed at some length by Mr. J. Bosisto, and the 
conclusion drawn is affirmative. The immunity of the Australian 
continent from fever, as compared with other countries of similar 
climate, is remarkable, and that in spite of grievous sanitary 
negledt in many towns. “ The various fever-types as found 
existing among us at times appear malignant, arising either 
from importation or from the existence of bad sanitary regula- 
tions ; but medical testimony is that their virulence is meteor- 
like, and dies at its opening day. No credit can be taken for 
any improved sanitary condition of our surroundings by ourselves 
in our towns and cities ; the influences operating there entice 
the fever-germ to frudtify and abound.” 
