1870.] Chemistry. 259 



in contact with the gas, so as to expose the fresh metallic surface — 

 there is no action. A glass vessel containing a piece of sodium was 

 weighed, and after the transmission of chlorine, under the circum- 

 stances above named, it was re-weighed, and found to be practically 

 the same. 



Mr. H. C. Sorby has published a detailed account of some 

 remarkable spectra of compounds of zirconia and the oxides of 

 uranium. The phenomena which he has observed are very com- 

 plicated, and reflect the highest honour on his philosophical acumen. 

 Some of the peculiarities in the spectra of compounds of the oxide 

 of uranium with zirconia, led Mr. Sorby and others, some time back, 

 to conclude that they were due to a new elementary substance. 



A rapid method for the quantitative estimation of sulphur in 

 cast-iron and steel is a great desideratum in metallurgical labora- 

 tories. Mr. Eggertz has described a process, based upon the shade of 

 coloration which small quantities of sulphuretted hydrogen produce 

 upon pure silver, or certain alloys thereof. In a glass-stoppered 

 bottle, a mixture is poured of water and sulphuric acid, to which is 

 added the metal, reduced to the finest possible powder. There is 

 then suspended, by means of a very fine platinum wire, in the 

 bottle, without touching the fluid, a clean piece of metallic silver, 

 the platinum wire being held squeezed between the stopper and the 

 neck of the bottle. The metal dissolves, in a moderately warm room, 

 within a quarter of an hour, so that the silver can be taken out and 

 examined after that time. The author has, by means of a series of 

 experiments, been enabled to construct a scale of numbers repre- 

 senting, according to certain shades of coloration, the quantities of 

 sulphur found. 



Naphthaline is a waste product occurring in large quantities in 

 gas works. The problem is how to utilize it. Dr. Ott has examined 

 its properties with this object. Pure naphthaline is similar in appear- 

 ance to alabaster, cracks easily in the warm hands, and becomes 

 negatively electric on being rubbed with silk. It melts at 174° F., 

 and boils at 452° F. Molten naphthaline absorbs a large quantity 

 of air, which is given off again on cooling ; according to M. Yohl, this 

 gas is pure oxygen. Molten naphthaline dissolves indigo with great 

 facility, forming a dark-blue violet liquid, from which the indigo 

 separates on cooling, forming fine shining needles like copper. 

 The amorphous sulphides of arsenic, tin, and antimony are also 

 readily dissolved, and likewise phosphorus, sulphur, iodine, the 

 iodide and chloride of mercury, arsenious, succinic, benzoic, and 

 oxalic acids. Professor Asa Gray has thoroughly tested and ob- 

 tained satisfactory results, proving that naphthaline may be advan- 

 tageously used in museums, herbariums, &c, instead of camphor, as 

 a very effective protection against moths and other insects. 



