TRANSACTIONS OF THE SECTIONS. 75 



acid, in five experiments, which varied from 43-89 to 43-97, the calculated 

 amount being 44-00 per cent. Pure carbonate of soda gave 41-52, 41-50, and 41-48 

 per cent. C O^. The calculated amount is 41-51 per cent. 



Peroxides are estimated by heating with sodic oxalate and hydric sulphate. A 

 specimen of manganese gave — 



1st experiment, 58-16 per cent. Mn 0^. 

 2nd experiment, 58-10 per cent. Mn Oj. 



It was further shown that potassic permanganate and potassic bichromate could 

 be easily and accurately analyzed by this process. 



By dissolving certain metals in dilute acid and measuring the volume of 

 hydrogen evolved, the pui-ity of the metal could be easily tested. It was shown 

 that different specimens of zinc gave an amount of hydrogen which varied con- 

 siderably. A specimen of pure iron prepared by Dr. Matthiessen gave, in the first 

 experiment, a volume of hydi-ogen corresponding to 100 per cent, iron, and in the 

 second experiment to 9993 per cent. iron. 



Other experiments with steel wire and cast iron were also given. A specimen 

 of magnesium gave an amount of hydrogen corresponding to 99-18 per cent, of 

 metal. The atomic weights of nickel and cobalt it was stated had been determined 

 by this process. 



On Jargonia *. By H. C. Soebt, F.R.S. 



I herewith send for exhibition at the Chemical Section what I believe to be 

 nearly pure zirconia and jargonia, prepared by a modified combination of the 

 methods described by Mr. David Forbes and myself. You will notice at once 

 that the zu-conia is perfectly white, whereas the jargonia is of a clear straw-colour. 

 This exactly corresponds with the difference between the opaque borax blowpipe 

 beads heated to redness, as described in my paper in the ' Proceedings of the 

 Eoyal Society,' and I am strongly inclined to believe that it is a characteristic 

 peculiarity. At first I thought it might be due to the presence of a small quantity 

 of iron, since zirconia containing a little of this peroxide is of a similar yellow 

 colour. When, however, that is digested in sulphide of ammonium it quickly 

 turns to a deep green colour, whereas this yellow jargonia does not turn at all 

 green. Subsequent experiments may show that the colour is due to some other 

 substance ; but, taking all the facts now known into consideration, it seems ex- 

 tremely probable that, after ignition, jargonia is of a clear straw-coloui-, paler than 

 that of timgstic acid, but deeper than that of ceroso-ceric oxide. 



On raising a Temperature higher than 212° F. in certain Solutions by Steam 

 of 212° F. By Peter Spence. 



Some twelve to fifteen years ago the author had occasion to require large masses 

 of liquor to be raised to a temperature of 228° Fahr. (108°-8 C), for the purpose of 

 extracting, by means of long-continued digestion at that temperature, alumina in the 

 form of sulphate of alumina from minerals containing that earth. As time was an 

 element of importance in his calculations, the author's aim was to heat the liquors 

 as rapidly as possible, but lead vessels only could be used with the acid liquors, and 

 as it was requisite to have an iron outside vessel next the fire, the heating was a 

 tedious operation. To overcome this loss of time, the author fitted up a digestino- 

 vessel so as to raise the heat rapidly to 212° F. (100° C), by injecting steam from 

 a steam-boiler into the mass of liquor ; and as soon as he had obtained that tem- 

 perature he stopped off" the steam and allowed the external fire to operate alone, so 

 as to raise the additional 16° F. (8°-8 C.) required, and to maintain the temperature 

 at 228° F. (108°-8 C), his impression being that above 212° F. (100° C.) the steam, 

 if kept on, would act as a cooling agent and prevent the temperature rising. The 

 combined operation was perfectly successful and went on for some time, acting, as 

 the author supposed, in accordance with his preconceived theory; but s'ome 

 circumstances led him subsequently to doubt whether it was so. He foxmd that if 



* Extract from a letter to Mr. Crookes. 



