MEETINGS OF SOCIETIES. 143 
moisture; moreover this dust had been collected at various places 
far distant from Krakatoa, and found to be volcanic and of the 
same nature as that from Krakatoa itself. As an illustration of the 
act that such fine dust can be projectedto great altitudes by vol- 
canic eruptions, he quoted an account by Whymper of an eruption 
at Cotopaxi where dust particles less than one twenty-five thousandth 
part ofa grain were shot out to great heights and afterwards blown 
as tar as Chimborazo. Probably this dust was kept suspended in 
the atmosphere because it was charged with the same kind of 
electricity as the earth and was hence repelled by it. Asa proof 
of the stupendous magnitude of the eruption, he stated that the 
report had been heard over an area 5000 miles in diameter—in 
Ceylon, Saigon, North and Central Australia—and that about 
half of the island had been blown clean away, leaving a vertical 
cliff and forming a fresh island about seven miles distant. This new 
island could not be due to an upheaval, because the sea bottom 
around had not been raised, but even somewhat lowered. An 
atmospheric wave which had passed four times round the earth had 
also been caused by the eruption. 
Dr. Haast agreed with Mr. Ringwood as to the eruption being 
the cause of the red sunsets, but thought that the disappearance 
of a part of the island was more probably due to a fault, and the 
appearance of a fresh island to an upheaval. An examination of 
the locality by a competent geologist would soon settle this point. 
Professor Hutton could not understand the great speed with 
which the dust cloud must have travelled. He thought it too 
great to be due to any terrestrial cause. The phenomena must 
however be due to something in the Earth’s atmosphere, otherwise 
they ought to be seen at mid-day as well asin the evening, and 
he was inclined to believe that they were caused by cosmical dust 
that had been caught up by the earth. 
Mr. Maskell asked if red sunsets had not been observed before 
the eruption of Krakatoa. 
Mr. Ringwood in reply said that similar sunsets had been 
recorded after other volcanic eruptions, at Vesuvius, the Andes, 
&c., but he did not know of any seen recently which could not be 
referred either to the eruption at Krakatoa, or to that at Alaska. 
ESNNEAN SOCIETY OF NEW SOUTH WALES. 
Sydney, 26th March, 1884.—C. 8. Wilkinson, Esq., F.G.S.,, 
F.L.S., President, in the chair. 
New member—Mr. J. F. Fitzhardinge, 
The following papers were read :— 
1. ‘On Plants which have become naturalised in New South 
Wales,” by the Rev. W. Woolls, Ph.D., F.L.S. In this paper the 
author not only deals with various importations, whether inten- 
tional or otherwise, of new and often injurious weeds, but also 
with the general and deliberate destruction of the native Flora, 
especially in timber. He also points out that many of our most 
valuable trees, as for instance the Myall (Acacia pendula), are dying 
out in consequence of the want of any kind of protection for the 
young plants. They are produced in abundance, but eaten down 
as fastas they grow. The paper contains a complete account 
of all the exotic Mono- and Di-cotyledons known in the Colony. 
