THE VICTORIAN NATURALIST. 29 



unfortunately of late been prevalent, the waters of the marshes and 

 billabongs are often completely evaporated, and the accumulated 

 sediments, full of diatom valves, are quickly dried to an almost 

 impalpable powder, which is readily gathered up and carried by 

 the wind at a considerable elevation for hundreds of miles. 



We have in this instance been so fortunate as to receive 

 confirmatory evidence from New Zealand that red rain, which is 

 beyond doubt identical with the samples we are describing, fell at 

 Otakia, in Otago. A slide of this material has been kindly 

 placed at our disposal by Professor Gregory. We find it only 

 differs from ours in that the dust particles, as may be seen 

 by reference to the photographs, are smaller than the bulk of the 

 material collected by us. This, as may be supposed, is no doubt 

 due to the larger mineral fragments having been filtered out by 

 gravitation in transit. But the diatom valves, owing to their 

 greater superficies as compared with their specific gravity, are 

 present in abundance, and serve to place the identity of the 

 deposit beyond question. We have, therefore, in this circum- 

 stance undoubted proof that relatively large objects — for some of 

 the valves are o. i mm. long and proportionately wide — are 

 carried by atmospheric agency considerably over i,ooo miles. 

 In all probability they would be conveyed over still greater 

 distances by varying air-currents, provided they were not thrown 

 down by condensation in the form of rain. 



Analysis of the Victorian Samples of Sediment. 



It was deemed desirable to have an analysis made of one of 

 the samples, and as the amount of material forwarded by Mr. 

 Ferguson was sufficient for this purpose it was handed, by the 

 courtesy of Professor Masson, to Mr. G. S. Walpole, of the 

 Chemistry Department, Melbourne University, who very kindly 

 undertook the work, and whose report is subjoined : — 



" The analysis of samples of dust from red rain collected by 

 Mr. Ferguson, of the Mines Department is as follows :— 



" The dust was passed through a sieve (80 meshes to the linear 

 inch), whereby some small pieces of straw, &c., were removed, 

 and then dried at 100° C. fer 6 hours. Finally it was dried for 

 one hour at 200"^ C. Two analyses of the material were made, 

 one by fusion and one by the hydrofluoric acid method. 



"Si O, ... ... ... ... 59.23 



Loss on ignition ... ... ... 10.28 



Al_, O, (containing Zr 0,) ... ... 14.01 



Total iron weighed as Fe, O3 ... 7 68 



Ca O ... ... ... ... 2.40 



Mg O ... ... -. ... 1. 91 



95 5^ 

 Alkali metals ... Trace only, not determined 



