414 



Messrs. Carpenter, Jeffreys, and Thomson [Nov. 18, 



water brought up in it would be derived from that stratum. Although it 

 can scarcely be supposed that the whole amount of the gases dissolved in 

 the very deep water is retained when the superincumbent pressure is 

 removed, yet it may be inferred, from the slight excess which still usually 

 presented itself, that the very deep water must include a greater propor- 

 tion of gases than that taken at or near the surface. 



20. A number of large glass bottles were provided, for bringing home 

 samples of Sea-water taken in various localities and at different depths ; and 

 of these Dr. Frankland kindly undertook to make careful analyses, which 

 should show not merely the proportions of its Saline constituents, but — 

 what has recently come to be a point of most unexpected interest (§ 23) 

 — the amount of Organic matter it may contain. The results of these 

 analyses are stated in Appendix II. 



21. But the determination of the nature and proportions of the dissolved 

 Gases could only be effected by immediate analysis ; and it was considered 

 by the Committee that it would be expedient to attempt this, notwith- 

 standing the difficulties which might be expected to arise from the motion 

 of the vessel. A method devised by Dr. Miller, as most suitable to the 

 circumstances, was carried into practical operation by Mr. W. L. Carpenter, 

 who succeeded in working this apparatus so efficiently during the First 

 Cruise, and obtained by means of it results of such singular interest, that 

 it was considered desirable that the same system should be followed 

 throughout the Expedition. This work was therefore committed in the 

 Second Cruise to the charge of Mr. Hunter, Assistant to Prof. Andrews of 

 Queen's College, Belfast ; and it was carried on during the Third Cruise 

 by Mr. P. Herbert Carpenter, according to the instructions he had received 

 from Mr. Hunter, whom he had accompanied in the Second Cruise. — A 

 general statement of the results obtained, which on the whole accorded 

 well with each other, is included in the present Report (Appendix I.) ; par- 

 ticulars of the method employed, with details of the analytical results, and 

 a fuller discussion of their rationale, will be furnished hereafter by Mr. 

 W. L. Carpenter. 



22. The accurate working of a Balance on board a ship at sea being ob- 

 viously impracticable, the Specific Gravity of every specimen of Deep-sea- 

 water brought up by the bottle was taken by Hydrometers specially con- 

 structed to indicate it within the required range to four places of decimals ; 

 and this was compared with the Specific Gravity of Surface-water. The 

 determinations obtained by this method, however, of which the results are 

 stated in Appendix I., cannot be regarded as equal in accuracy to those ob- 

 tained by the Balance ; and greater reliance, therefore, is to be placed on the 

 Specific Gravities of the samples analyzed by Dr. Frankland (Appendix II.). 



23. Further, tests devised by Dr. Angus Smith* to determine the amount 

 of Organic matter (1) in a non- decomposing, and probably therefore an assi- 

 milable state, and (2) in a state of decomposition, were frequently applied ; 

 with the remarkable result (Appendix I.), which has been since fully con- 



