222 THE POPULAR SCIENCE MONTHLY. 



At most, lead and zinc are susceptible of being converted into oxide or 

 carbonate in a moist medium ; but under such conditions they are dis- 

 integrated and fall into dust, while the tablet is quite compact and 

 covered with a very fine and extremely clear inscription. Its real 

 nature was therefore a riddle. We then first carefully sounded it, and 

 ascertained that there was no central metallic leaf in its thickness. 

 Chemical analysis indicated that it was a pure, crystallized carbonate 

 of magnesia — a substance that is more refractory to dilute acids and 

 atmospheric agencies than carbonate of lime. The polishing of the 

 tablet appeared to have been completed with the aid of an almost in- 

 sensible trace of fatty matter, which manifested itself on calcination. 

 We observe here that our magnesia and its salts were not known in 

 antiquity and the middle ages, and that pure and crystallized carbon- 

 ate of magnesia is a very rare mineral, and was not known by Haiiy 

 at the beginning of the present century. But in intimate association 

 with carbonate of lime it constitutes dolomite, a very abundant rock. 

 Carbonate of magnesia is found principally in veins intercalated in tal- 

 cose schists, serpentine, and other magnesian silicates, where it results 

 from the slow decomposition of the rocks by natural agencies. The 

 material of the tablet in question also includes a few traces of silica, 

 which indicate the same oi'igin. The choice of so exceptional a min- 

 eral for the fabrication of a sacred tablet can not have been made by 

 chance. It doubtless responded to some particular religious idea. At 

 any rate, it proves that the Assyrians were acquainted with the carbon- 

 ate of magnesia as a proper substance. To what word did this tablet 

 correspond in the inscription, in which it appears to figure under the 

 name of one of the supposed metals ? Notwithstanding the absence 

 of a special denomination on this tablet, M. Oppert believes that it was 

 designated by the word a-bar, which had been supposed to mean tin. 

 I thought it might be useful, in the effort to obtain new light in this 

 matter, to analyze the substance of which the great bulls in the Louvre 

 Museum are made, and see if it contained dolomite. The analysis de- 

 termined, however, that this matter Avas a crystallized carbonate of 

 lime representing the physical constitution of marble, or rather of 

 that variety of limestone which was formerly confounded, under the 

 name of alabaster, with anhydrous sulphate of lime. 



While I was studying the tablets of Khorsabad, M. Heuzey called 

 ray attention to some metallic fragments of a vase and a votive fig- 

 urine which came from M. de Sarzec's excavations at Tello. The 

 fragment represents a portion of a cylindrical circular band which 

 formed the mouth of a cast vase, and had been prepared by melting 

 and casting. A part of the throat that separated this band from the 

 body of the vase proper can still be seen. It is very simple in form, 

 and without any inscription or even light delineation. The surface 

 is covered with a very thin, yellowish-black patina. The mass is 

 formed of a brilliant black metal, the fracture of which exhibits vo- 



