Prof. How on the Mineralogy of Nova Scotia. 275 



it would not be distinguishable from a particular form of the 

 general integral. 



There would, I think, be no difficulty in extending the method 

 of solution adopted in this communication so as to take into 

 account the change of the moon's declination, and to include also 

 terms of the second order. But I am not prepared to undertake 

 the labour of going through the details of the analytical and 

 numerical calculations which would be required. 

 Cambridge, March 11, 1870. 



XXXV. Contributions to the Mineralogy of Nova Scotia. By 

 Professor How, D.C.L. } University of King's College } Wind' 

 sor 3 Nova Scotia. 



[Continued from vol. xxxvii. p. 271.] 



V. New Forms of the Borates in Gypsum — Crust of Glauber salt 

 and Epsomite containing Boracic Acid on Gypsum — The Bo- 

 rates as Fluxes in Welding — Loss and Gain of Water by Va- 

 rieties of Crystallized Gypsum. 



JtfATROBOROCALCITE in distinct Crystals.— -Like many 

 other minerals of complex composition, natroborocalcite, 

 as I have called it in former papers (Ulexite of Dana*, from the 

 name of its first analyst), has engaged the attention of many in- 

 quirers, who have expressed different opinions as to the compo- 

 sition of the species. In addition to the fourteen analyses given 

 by Dana, who furnishes a ratio from the results of Rammelsberg 

 and one from mine, others have been published, from which dis- 

 cordant conclusions have been drawn. "With regard to Ram- 

 melsberg's formula, Dr. Lunge f says " it cannot be denied 

 that the percentage of boracic acid found falls much too short 

 of that required by his formula, and agrees better with that of 

 Kraut." This formula, attributed to Kraut, is really mine by 

 priority, as not overlooked by that gentleman ; but it received 

 his name from Dr. Lunge because of his endeavours to show 

 its general validity from many other analyses than minej. 

 When the circumstances under which the mineral occurs are re- 

 viewed, the reason of the want of agreement among analysts is 

 manifest. The most abundant supply is obtained from Southern 

 Peru, where, known as tiza, it is in the closest association with 

 nitrate of soda, Pickeringite, Glauberite, salt, gypsum, chlo- 

 ride of calcium, and other substances; and specimens from 



* Mineralogy. Fifth edition, p. 598. 

 t Chemical News, vol. xv. p. 86. 

 X Loc. cit. p. 214. 



T2 



