78 Scientific Production of Some Acids. 



hinc inde transversim diffractis (latit. 1 — 3 mm.), subtus 

 dense fuligineo-pannosis vel spongiosis ; medulla albida 

 K — C — ; apotbecia rufo-fusca vel fusco-nigra, plana (latit. 

 1 — 4 mm.), receptaculo extus furfuraceo sed non rugoso et 

 margine tenui nonnibil intlexo ; sporse numerosaB (100 et 

 ultra), incolores, simplices, lineares sed arcuatse vel crescen- 

 ticse, -009— -013 x -0025— '003 mm. Iodo gel. bym. vix 

 tincta, theca? cserulescentes. 



Cortieola, Owen Sound in Canada (Mrs. Roy). 



Affinis P. tceniatce (Nyl.) sed distincta. 



Tbe receptacle of the apotbecia is externally yellowish, 

 and finely tomentoso-furfuraceous, as in tbat of several 

 Peltigerce. 



Art. XI. — Suggestions for a Neiv and Economical Method 

 for the Scientific Production of some Acids. 



By Edward Lloyd Marks, Lecturer on Chemistry, &c, 

 School of Mines, Sandhurst. 



[Contributed October 14th, 1880.] 



Reflecting upon the important roles played by Silica in 

 the formation of numerous natural and artificial bodies, also 

 upon its application in the manufacture of technical products 

 of great utility in scientific and industrial pursuits, it has 

 occurred to me that advantage might be taken of its 

 chemistry in a way that might be useful in the production 

 of some acids, and possibly on a large scale, where circum- 

 stances are favourable. 



It will be remembered that, at varying temperatures, 

 opposite effects may be produced with the same materials — 

 affinities stable at a low may be reversed by a high heat, 

 and conversely : numerous facts might be cited to verify the 

 statement. The stability of the alkaline Silicates is readily 

 overcome by a moderate heat, whilst in consequence of the 

 non-volatility of Silica, even at the highest temperatures, 

 salts of volatile acids are readily decomposed by it, their 

 acidulous radicals being liberated; consequently, open for 

 collection. 



