APPENDIX. XV 



Muriate of Magnesia, ... . 0.94 



Alcoholic solution < Muriate of Soda, 2.10 



Nitrates (of Soda and Potash,) - 2.46 



7.40 

 The presence of Magnesia was determined with much care, as to it may be attribut- 

 ed the purgative qualities of this water. 



No. VL 



ABSTRACTED RESULTS OF MARINE OBSERVATIONS, 

 Made by G. A. Prinsep, Esq. and detailed in a letter of 7th March, 1823, Bombay. 



By J. Prinsep, Esq. 



1. In the course of several voyages in the Atlantic and Indian oceans, Mr. G. 

 Prinsep has turned his attention to the solution of the two marine problems inter- 

 esting to navigators as much as to philosophers, namely, "the Saltness or Specific 

 Gravity, and the Temperature of the Ocean, on different parts of its surface." 



He has compared his own numerous observations with a series made by Dr. A. 

 Russell and myself on our passage to India in 1819, and with another subsequent 

 voyage by Capt. Weynton : the result of his labors was sometime ago communicat- 

 ed to Dr. Marcet, of the Royal Society, but our meeting in Calcutta last winter hav- 

 ing given occasion for the revisal of some of his Tables, when we compared our dif- 

 ferent Instruments together, this circumstance produced another letter to Dr. Mar<- 

 cet,* of which my brother has forwarded a copy. I have selected the general facts 

 which he has deduced from the whole range of observations ; as, in reality, the de-s 

 ductions themselves can be the only interesting part of such investigations to all 

 but to the actual investigators. 



I. 2. The absolute specific gravities of various parts of the Ocean, reduced to 

 the Standard Temperature 60° Farnh. are as follows : 



Mouth of the British Channel, 1027.2 



Coast of Portugal to the Tropic, 1027.9 



Thence to 15° North Latitude, 1027.9 



* This worthy friend and excellent chemist died before this letter ooxdd have reached England, 



