COMMENTATIO ao QÜAESTIOICEM CHEMICAM. 47 



Magnesicus = MgC. Carbonates, qui aqua aolubiles sunt , etiam aqudCaIcis, Barytae at* 

 que Strontianae decomponuntur. 



§. 17. 



Sesqui-earhonates illa acidi carbonici cum oxydia vocantur connubia , in quibus quan» 

 titas oxygenü acidi , ter copiam oxygenii in basi superat ; quae combinationis ratio - 

 primum a Bertholleto A°. 1809 detecta et indicata est. Sesqui - carbonas Natricus 

 =r Na" C' uativus exstat, et etiam aeque ac sesqui-carbonas Kalicussr K* C^, coquenda so- 

 lutione singulorum illorum bi-carbonatum , parari potest , qua operalione quarta acidi 

 carbonici pars e bicarbonatibus expellilur (12). Praeterea innotuerunt sesqui-carbonas 

 Ammonicus= 2Sftt* + C^ et Baiylicus = Ba^C'. 



§. 18- 



Bi-carhonales tandem illi sales sunt , in quibus oxygeaii quantitas in acido se habet ad 

 ejus quantitatem in oxydo uti 4:1. Hi igiturduplo majorem acidi quantitatem continent 

 quam carbonates, quod Wollaston, Vir acutissimus , ingeniosissimo experimento dilu- 

 cide demonstravit (i3). Quinque innotuerunt hujus generis connubia, nempe bi-carbo- 

 nas Ammonicus = ^H* C* + 25t . Baryticus = BaC*, Kalicus := KC*, Magnesicus =: 

 MgC" et Natricus =r NaG". Bi-carbonas Baryticus et Magnesicus autem solidi obtineri 

 nequeunt. Omnes aqua sunt solubiles, non ita facile autem ac carbonates solubiles, 

 excepto carbonate Lithico ( i4 ). Bi-carbonates , quorum bases igni resistunt , igniendo 

 tantummodo dimidium acidi sui amittuut , atque in carbonates convertunlur. Doctiss. 

 Wetzlar (l5) vestigia priscorum chemicorum secutus, enumeralis etiam bi-carbonatem 

 Plumbicum addere voluit , qui, illo auctore, aeque ac bi-carbonas Baryticus et Magnesi- 

 cus non nisi in statu liquido exislere potest. 



(is) Berzel. Jahresb, 1827. 1G8. Boussingault ia Ann. de Chim. et de Phys. XXIX. 110 et 283. 



( i3) Cf. Philos Transact. 1808. 97. o Let two grains of fully salurated and wel crystallized carbo- 

 n nate of Potash be wapped in a piece of thiu paper , and passed up into au inverted tube , fiUed 

 « with raercury and let the gas be extricated firom it by a sufficient quantity of rauriatic acid , so that 

 • the Space it occupies may be raarked upon the tube, Next, let foiir grains of the same carbonate 

 «1 be cxposed for a short tirne to a red heat; and it will be found to have parted with cxactly lialf 

 « its gas , for the gas extricated from it in the same apparatus will be found to occupy exactly the 

 c same Space , as the quantity before obtained frora two grains of fully saturated carbonate. 



(i4 ) et d'Arcet in Ann. de Chim. et de Phys. XXXI. SB. 



(i5) Ct. Schweigg. Jouru. LIV. 3ä8. 



