ANALYSIS OF THE CHINESE RICE-STONE. 375 



gen and azot as the preceding. In an experiment of this 

 kind, when twenty quarts of ammoniacal gas were decom- 

 posed with every precaution for condensing the water, that 

 should have been formed if ammonia contained ■§■ of oxigen, 

 none was obtained. 



The decomposition by the electric spark shows no trace of No oxigen in^ 

 humidity, or of oxidation, when an iron wire is employed ; ti ^ n by°decui- 

 yet one or other of these effects must inevitably take place, city, 

 if there were any oxigen in ammonia. 



VI. 



Analysis of the Chinese Rice-Stone, with some Observa- 

 tions on the Yu ; by Mr. Klaproth *. 



1 HE rice-stone, of which the Chinese make cups, and Rices . toncan 

 other vessels, which are occasionally brought to Europe, is & nct 

 an artificial production, the component parts of which are 

 yet unknown. Authors are by no means agreed on the 

 origin of its name. Storr informs us, that many collectors ^ tobe P re * 

 of curiosities in Holland assured him it was actually pre- P r 

 pared from rice, which was hardened by the addition of 

 other substances. Bruckmann on the other hand supposes, 

 that it received its name from its resemblance to transparent 

 rice. It has also been considered by some as alabaster : by 

 others as chalcedony, or one of its varieties, cacholong; 

 and lastly as the problematic stone, or yu, which will be 

 mentioned hereafter. Mr. Kratzcnstein, of Copenhagen, 

 has at length ascertained what this substance is, and gives 

 the following description of a cup. 



This substance is a fusible glass, resembling in colour a A fusible glass. 

 white jelly. It is formed in a mould of two pieces, while 

 it is soft. It is ornamented with figures and handles in re- 

 lief. The sharp edge occasioned by the mould was still 

 observable. It is so hard as to scratch glass, and is much 

 more difficult to cut than marble. Its fractnre has a dull 

 lustre, like that of starch jelly dried. Its colour and trans- 

 parency much resemble alabaster, 



* Annates de Chinie, vol. lxix, 3Q2. From GehlerCs Journal. 



Crell 



