272 



Dr. Heddle on the Galactite of Haidinger, 



Dunmore Tide, Table F. 



DiflFerence of observed and calculated times of vanishing at high 

 water, expressed in lunar days. 



As;e of lunar tide =5<1 14*'. 



The agreement between the calculated and observed tides 

 shown in the preceding Tables is excellent ; and since the tide 

 itself is small, it proves the remarkable care with which the ob- 

 servations were taken at this station. 



In the next section, which will conclude this abstract, I intend 

 to give some general deductions from the preceding facts, and to 

 compare the results of observation with theory. 

 [To be continued.] 



XXXIV. On the Galactite o/ Haidinger, with Analyses of Scotch 

 Natrolites. By Dr. Heddle*. 



IN seeking out specimens of " Galactite " for analysis, my first 

 difficulty lay in ascertaining if they were the species to which 

 Haidinger had given this name ; and finding that Mr. Rose's 

 Galactites came from a totally difi'erent part of the country from 

 that which aff"orded my own specimens, I bethought myself of 

 writing to Mr. Greg, the catalogue of whose collection was com- 

 piled by Haidinger himself : the result was that Mr. Greg sent 

 me Galactites from two localities, neither of which I had imagined 

 to be the true one. 



As Mr. Greg's localities must be correct, I give them the pre- 

 ference in my analyses. The first was Glenfarg in Fifeshire ; 

 the specimen sent was white, though not very milky; its ana- 



* Communicated by the Author. 



