[ 47 ] 
of pure alkali by my computation being 78,6 grs. fhould afford 
by the above obfervation 284,5 grs. therefore 60,5 were loft. 
Mr. Wenzel attributes to 110 parts of fal ammoniac 56 of 
alkali and 54 of acid, but itis plain he was deceived both by 
the mifcalculation of the quantity of real alkali in his aerated 
alkali, and by the volatilization of part of the falt during the 
evaporation of the faturated folution. 
Of the Relation. of the Nitrous Acid to Calcareous Earth: 
To 400 grs. of fpirit of nitre, whofe fpecific gravity was 
1,2754, I gradually added in temperature 58° fome finely pow- 
dered white ftatuary marble, whofe grain in the fra@ture re- 
fembled that of fugar;, of this 136 completely faturated the acid 
in two days, the lofs of air was 61 grs. or nearly 45 per cent. 
This proportion of air is much greater than that which I found 
fome years ago, but at that time I diffolved without applying 
heat, the marble in dilute vitriolic acid, which does not eafily 
penetrate the whole mafs, as the felenitic cruft formed during 
the firft accefs of the acid proteéts the remainder from its 
action. 
Turis acid contains 45,7 per cent. ftandard, confequently the 
400 grs. employed contain 182,8 of ftandard ; and fince 182,8 
_ parts ftandard took up 136 of this marble, 100 parts ftandard 
fhould take up 74,4. An opportunity was hereby afforded me 
of 
