Mr. Phillips on a neixi Salt of Perchloride of Mercury. 129 



Comparison of Tides observed January 1 /"o 1 3, 1 830, xmth the 

 Tide Tables in the British Almanac. 



The tide-tables in the British Almanac are calculated to 



apparent time, as are all the tables in the same publication, 



as the observations are in the mean time, the mean error 



. -, 7010-69-30 A • ^ 1 



A.M. = — = 4 mmutes nearly 



P.M. = ^337-63 0_ ^ g minutes nearly. 



XVIII. On a new Salt obtained by the imrtial Decomposi- 

 tion of Perchloride of Mercury. By R. Phillips, i^.iZ.S. 

 L. Sf E., Sfc. 

 ''■"'HE action of chlorides and water, as a theoretical subject, 

 ■■■ has perhaps occupied more than a requisite degree of at- 

 tention : it has however again lately excited my notice, and the 

 experiments suggested by it have led to the formation of a mer- 

 curial salt which has not, I believe, hitherto been described. 



Although when some chlorides, — those, for example, of an- 

 timony and bismuth, — are mixed with water, we have demon- 

 stration of the production of muriatic acid and a metallic oxide 

 by their mutual decomposition ; yet the supposition of similar 

 action is sometimes attended with considerable difficulty, and 

 especially when the base of the chloride has but slight affinity 

 for oxygen, as in the instances of gold and mercury. 



N.S. Vol. 7. No. 38. Feb. 1830. S With 



