40 Dr. Serturner on the Combination of Acids [JuLir, 



acids) is not so intimately combined as the alcohol in the alco- 

 holic acids. We must, therefore, give them the name of hydrous 

 acids, in the same way as we call the others alcoholic acids ; for 

 they combine without any decomposition with the weak saline 

 bases forming hydrous salts. With the strong saline bases, 

 they do not form such compounds ; for when they unite with 

 them, the water, their second constituent, is separated and driven 

 off. Thus we are acquainted with hydrous sulphate of alumina, 

 but with no real anhydrous sulphate of alumina ; for alumina is 

 not capable of separating sulphuric acid from water. We know 

 likewise, from the doctrine of definite proportions, that alumina 

 ought to combine with a greater proportion of sulphuric acid 

 than it actually does ; for water not merely diminishes the strength 

 of acids, but likewise their capacity for the saline bases ; as is 

 the case with the alcohol in the alcoholic acids. The truth of 

 this assertion is proved by the neutral protoinothionate of lime, 

 which, when heated, is converted into neutral sulphate of lime, 

 while a portion of free sulphuric acid is disengaged. 



As the water is only weakly combined in the strong acids, the 

 powerful saline bases, as barytes, potash, &c. separate it, and 

 form, when placed in contact with hydrous sulphuric acid, pure 

 sulphates. Hydrous sulphate of the powerful saline bases do 

 not exist. The hydrates of these are nothing else than combina- 

 tions of the salts and water. In the alcoholic acids, the alcohol 

 is more firmly combined than the water in the hydrous acids ; 

 accordingly they form alcoholic salts both with the strong and 

 weak bases, without any exception ; and we have not merely 

 alcoholic sulphate of alumina, but likewise alcoholic sulphates of 

 barytes and lime. 



These observations throw light upon the dispute which exists 

 at present respecting the compounds of chlorine and hydrochloric 

 acid (as it has been called). The weak saline bases, which are 

 not capable of separating the water from the muriatic acid, unite 

 with it so as to form hydrousmuriates ; but the strong bases 

 form real muriates, possessing the property of separating the 

 muriatic acid from the water. Hence it happens that while the 

 salts which contain the hydrous acid are easily decomposed by 

 heat, the others, on the contrary, are not in the least altered by 

 heat ; for as the hydrous acid contains in the water a basis, 

 according to the condition of its constitution, it does not stand 

 in need of the saline basis, being already united to the water. 

 The heat does no more than separate the saline basis, and unite 

 itself to the hydrous acid in its stead, constituting a thermate 

 in which the heat is united to the hydrous acid like a base. The 

 hydrous and alcoholic acids are always weaker than the strong 

 acids of which they are composed ; while the water and the 

 alcohol diminish their capacity for the saline bases.* 



» The volatile acids, which contain heat, and being united with it into thcr- 

 roates, do not require water, are not to be ranked with these. Heat in them con- 



