EDITORIAL NOTES. 
The physical and chemical investigations conducted by Mr. J. Y. Buchanan, 
during the three and a half years’ cruise of H.M.S. Challenger, are among the 
most important and valuable of the Expedition. 
Mr. Buchanan collected daily, with much care, samples of the surface 
water, and determined the specific gravity. At all Stations, a slip water bottle 
was attached to the sounding line, and the specific gravity of the specimen 
of bottom water thus collected was also ascertained. At every Station, where 
practicable, waters were collected from intermediate depths at 25, 50, 100, 200, 
300, 400, and 800 fathoms from the surface, with a stop-cock water bottle 
attached to a separate sounding line, under Mr. Buchanan’s personal super- 
vision. The specific gravity of these waters was also determined. 
The routine chemical work of the Laboratory consisted in boiling out the 
gases from, and in determining the carbonic acid in, as many samples as 
possible. 
A very large number of samples of sea-water were collected from the 
surface, bottom, and intermediate depths, and preserved in glass stoppered 
bottles. These were either sent home along with other collections from 
various ports touched at during the Expedition, or brought home by the ship. 
It is difficult for any one, except those who actually witnessed the daily 
work at sea, to form an adequate idea of the labour, skill, and continuous 
effort required to carry on these observations in all sorts of weather, and to 
form, and bring home successfully, collections and observations like those 
which have resulted from Mr. Buchanan’s exertions. 
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