64 REPORT — 1855. 



works called it "congealed water," and supposed that it could not possibly have 

 been brought there originally and placed in the position where it was found. The 

 crystals had spread themselves over a stratum of clay, and had probably been formed 

 by the action of slowly decomposing sulphurets on the carbonate of lime in the water 

 or earth. 



Experiments on the Compounds of Tin ivith Arsenic. By Ed. Haeffely. 



These experiments had led to this practical fact, that the danger of using any arse- 

 niates in stannates of soda might be obviated by the use of pure stannate of soda 

 alone. 



On a new Form of Cyanic Acid. By the Baron Von Liebig, Munich. 



In the course of some experiments on the fulminate of mercury, I observed that that 

 compound, when kept boiling in water, changed its colour, and lost its fulminating 

 properties. On examining the change that had taken place in the composition of the 

 fulminate, I discovered a new acid, which had exactly the composition of cyanuric acid, 

 but which differed entirely from that acid in its properties, and in the properties of the 

 salts which are produced with the alkaline bases — salts remarkable for their beauty 

 and for the distinctness of their crystalline form. Taking for the equivalent of hydrated 

 fulminic acid the formula C2, NO, HO, the new acid is produced in a very similar 

 manner. The elements of three equivalents of fulminic acid unite to form one equi- 

 valent of the new acid, to which 1 shall give the name of fulminuric acid. This acid 

 is monobasic. Its salt of silver is soluble in hot water, and crystallizes from it in long, 

 silky, white needles. The alkaline salts of the new acid are very easily prepared by 

 boiling the fulminate of mercury with an alkaline chloride. The fulminate of mercury 

 is first dissolved ; then gradually two-thirds of the oxide of mercury precipitates, and 

 the alkaline fulminate, with a certain quantity of chloride of mercury and potassium, 

 remains in the solution. By employing the chloride of sodium, or the chloride of 

 barium, we obtain, of course, a salt of the new acid, with a base of soda or of barytes. 

 With chloride of ammonium an ammoniacal salt is obtained, the crystals of which are 

 distinguished from all others by their adamantine brilliancy, and their high degree of 

 power and lustre. These crystals belong to the Klinorhombic system, and possess 

 double refraction almost as strongly as Iceland spar. The hydrated acid is easily 

 obtained by decomposing the basic lead salt by means of sulphuretted hydrogen. It 

 has a strongly acid reaction, and when reduced by evaporation to a state of syrup, it 

 is transformed by degrees into a crystalline mass, which dissolves in alcohol, and which, 

 by the action of acids, is changed hito carbonic acid and ammonia. 



Baron Liebig made a few observations on a new mode of making bread introduced 

 into Germany. Lime-water had been used in the preparation of the dough, and the 

 loaf was rendered still more nutritive than that made by the common mode. 



Baron Liebig handed in for inspection a large bar of the new and interesting 

 metal Aluminium. 



On the Commercial Uses of Lichens. By Dr. A. L. Lindsay. 



On the Chemical Composition of the Waters of the Clyde. By Stevenson 

 Macadam, Ph.D., F.R.S.E., F.C.S., Lecturer on Chemistry, Surgeons^ 

 Hall, Edinburgh. 



This communication is the first of a series which the author has undertaken in 

 order to determine the chemical composition of the rivers of Scotland. The present 

 examination was confined to the river and firth of Clyde, from Dalmarnock Bridge 

 down to Arran. Specimens of the water at the more prominent stations were pro- 

 cured by the author, and separately analysed. Three points were determined, viz. 

 1. the specific gravity; 2. the amount of saline matter j and 3. the quantity of 

 chlorine. 





