Intelligence and Miscellaneous Articles. 257 



In addition to this general notice there is nothing stated ; the sub- 

 ject, however, has now assumed such importance, that minute and 

 careful descriptions are desirable. It is important to know the di- 

 rection of the striee with reference, both to the points of the com] ass, 

 and the bedding of the rock ; whether they are parallel at remote 

 points, or divergent ; and whether they coincide with or are trans- 

 verse to, the course of the valleys, and the great dominant faults. 

 The localities mentioned by Dr. Buckland are not embraced in my 

 paper ; they were not known either to Mr. Wakefield or myself. 

 That of Fox Howe garden is of great interest owing to its peculiar 

 position, sheltered by a high hill on the west and north-west. 



I hope to obtain during the ensuing summer a series of minute 

 and accurate observations on the localities above-mentioned, as well 

 as on the valleys opening northward from the central group of moun- 

 tains, jll J-Uii|<Ifc to 



I am very faithfully yours, 

 6 Lansdowne Crescent, Glasgow, "^ ' iuo, James Bkyce. Jun. 



Feb. 3, 1851. 



.;o 'iol jijiiaiii 



ON SOME PROPERTIES OF BORACIC ACID, AND ESTIMATtON^OP- 

 ITS QUANTITY. BY PROF. H. ROSE. 



The quantitative determination of boracic acid is attended with 

 difficulties which have hitherto defeated any method of immediately 

 effecting it. When this acid Is dissolved in water, it is well known 

 that its total quantity cannot be ascertained by merely evaporating the 

 water ; moreover when the acid thus obtained is melted on a platina 

 crucible, its weight constantly diminishes, unless contact of the air 

 be avoided. This loss is still more considerable when the heat is 

 raised to redness ; but it is reduced to a few millegrammes when the 

 calcination is effected in an atmosphere which is not moist. If, on 

 the other hand, the boracic acid obtained be moistened with a drop 

 of water, and be again heated to redness, the loss of weight amounts 

 to some centigrammes, and it is still greater if a few drops of 

 alcohol be used. The best method of avoiding loss during the fusion 

 of boracic acid, is to pour on its surface a small quantity of carbonate 

 of ammonia. 



It has been proposed to avoid the volatilization of boracic acid on 

 evaporating its aqueous solutions by saturating them with ammonia 

 before evaporation ; but the affinity of boracic acid for ammonia is 

 so weak, that the latter escapes with the vapour of the water. 



The addition of chloride of ammonium to an aqueous solution of 

 boracic acid docs not prevent its volatilization. When, after adding 

 this salt, the whole is evaporated, and the dry residue is calcined on 

 a platina crucible till vapours of chloride of ammonium cease to arise, 

 a residue is obtained, which, at the temperature when pure boracic 

 acid fuses, cannot be made to do so. If the residue be treated with 

 water, there remains nitruret of boron in the state of a grayish-white 

 powder. The quantity of this substance varies, and sometimes even 

 it is not produced. 



Phil Mag. S. 4. Vol. 1. No. 3. March 1851. S 



