MEMOIR OF THE LATE DR THOMAS CHARLES HOPE. 429 



He added examples thus — 



1 atom of base to 1 of oxygene, oxide of base. 

 1 ... 2 ... bis oxide. 



1 ... 3 ••- ter oxide. 



2 atoms of base to 1 of oxygene, dis oxide. 



3 ••• 1 ... tris oxide. 



2 ... 3 ... dis-ter oxide. 



and so forth. 



The general adoption of some such nomenclature, he conceived, would give 

 a desirable accuracy to chemical language. 



In a conversation with Dr Hope in the early part of 1837, I noticed the dis- 

 cordant opinions held by various philosophers on the maximum density of sea- 

 water, and asked whether he had applied to this fluid the same beautiful and 

 simple investigations by which he had ascertained the point of greatest density 

 in fresh water. He replied in the negative. I strongly recommended the subject 

 to his notice ; because, as it appeared to me, several geologists and hydro- 

 graphers had deduced erroneoiis explanations of certain phenomena in the ocean 

 from this undecided point. I added, that I should long ago have attempted to 

 solve it, had I not considered that it would have been an interference with a sub- 

 ject he had already so ably discussed. He thanked me for the hint, and the 

 consequence was, the completion of the series of experiments, which he commu- 

 nicated on the 2d of April 1838, to the Society, in an " Inquiry whether seanwater 

 has its maximum density at some degrees above its congealing point, after the manner 

 of fresh watery Most philosophers seem to have assumed, that sea-water followed 

 the same law in cooling as fresh water ; and its greatest density was generally 

 considered to be at temperature 36^° F. 



Dr Hope first tried the effect of cooling sea- water from 40° in vessels shaped 

 like large thermometers, and found that it continued to shrink, by a diminution 

 of temperature, like other bodies. He afterwards employed the same apparatus 

 with which he had examined the peculiarity in fresh water ; and he found, that 

 in cooling from 40° to its freezing point, the coldest water was invariably at the 

 bottom of the vessel. Therefore, the striking anomaly which so remarkably dis- 

 tinguishes the cooling of fresh water, does not take place in sea-water. The 

 importance of this conclusion will be manifest to those who have examined the 

 theories of oceanic currents, and the remai'kable fact, that the existence of banks 

 or shoals in the ocean is marked by a fall in the temperature of the superin- 

 cumbent water. 



Dr Hope reserved the examination of the precise point of the maximum 

 density of sea-water for a future communication — which was never made. 



In ] 843, the Society had two communications from Dr Hope. The first 

 was — " Observations an the Flowers of the Camellia Japonica, Magnolia Grandi- 

 Jlora, and Chrysanthemum Leucanthemum." This paper was read on two evenings, 



