A History of Hindu Chemistry from the Earliest Times to the Middle of the Sixteenth Century A.D. v1.c21.32

v1.c21.32

The Chinese method as also that of the Latin Geber recommends the addition of saltpetre as thereby more of corrosive sublimate would be formed than calomel, and this purpose is equally served in the process of Bhāvaprakāsa which uses, over and above brick-dust, *gairika* (red ferruginous earth, see p. 139, thus further increasing the chlorinating capacity. Professor Divers is of opinion that the sulphuric acid set free by alum acts upon sodium chloride giving rise to hydrochloric acid (loc. cit). and does nothing more; our view is that the sulphuric acid simultaneously acts in a two-fold capacity; first, it liberates hydrochloric acid; secondly, it acts upon mercury forming mercurous or mercuric sulphate as the case may be and then double decomposition takes place between the two thus: