Part 4 - Preparation of cinnabar at laboratory

Hingula is of two kinds, viz, (1) that which is obtained in mines and (2) that which is prepared at laboratory by the combination of mercury and sulphur. The process of preparing cinnabar at laboratory is as follows:—One part of mercury (which need not be purified) and four parts of sulphur are to be placed in an iron pot, and heated for some time. The amalgam is then to be broken into pieces and put into a glass bottle, previously coated all round with mud and rag one anguli deep, and dried in shade. The bottle is to be heated by means of a Baluka-yantra for one day with mild heat. It is then to be heated for five days continuously by means of a fire increasing gradually in intensity at a uniform rate. The heating is then to be discontinued and the contents of the glass bottle taken out on the seventh day. The product will be found to be hingula.