430 PHILOSOPHICAL TRANSACTIONS. [aNNO I678. 



proportion less rich in gold : both which are contrary, in repeating the melting 

 of the regulus with fresh antimony, as in the former experiments. 



The remaining antimony being reduced to a regulus by firing with nitre 

 and tartar, of each equal weight to itself, and that regulus exhaled on the cupel, 

 there remained 1 Q grains of gold. This was less fine than that obtained from 

 the first antimony, in the former experiment of passing gold through several 

 parcels of antimony ; though losing little sensibly in weight, upon melting 

 with a strong heat and blast upon it. So that the impurity was not from any 

 remaining antimonial substance in it ; but from the silver and copper mixed 

 with it in the first alloy. 



III. A parcel of crown gold, weighing 824- grains, was melted down with 

 an ounce of antimony ; and the antimony exhaled in the crucible to a regulus. 

 Then the antimonial part of that regulus was exhaled on a cupel. Whereupon 

 there remained 84 grains: which was more than the first gold by li grain. 

 This must happen for want of a heat strong enough at last to force off all the 

 antimonial substance. Whence afterward, upon melting in a crucible, it came 

 short 4 grains ; 80 grains, which was but 24- grains shert of the first quantity, 

 and is the least part of the proportion of copper that must be in it, according 

 to the usual alloy of crown gold: which is generally two parts to one of 

 silver, or at least the half. So that antimony, in a far greater proportion, 

 does not so much as lead in exhaling or separating copper from gold, if the 

 work be done merely by exhalation ; but only retains it with itself, whilst the 

 gold separates and settles in a regulus at the bottom. Neither is it so destroyed, 

 but that it may, in part at least, be united to the gold again. That there re- 

 mained copper in this gold, appeared farther by the black complexion of it 

 on annealing. As also by the loss on working it with lead on a cupel : where- 

 upon it came forth 76 grains, i. e. 4 grains short. 



Account of a monstrous Birth, communicated by Dr, S. Morris. N° 138, p. 96 1. 



This monstrous female birth had two heads, both the faces very well shaped. 

 The left face looked swarthy and never breathed; that head was also the 

 larger. The right head was perceived to breathe ; but not heard to cry. Be- 

 tween the heads was a protuberance, like another shoulder. The breast and 

 clavicles very large ; about 7 inches broad. It had only 2 hands and 2 feet. 



The brain, in each head, was very large. The spina dorsi, from the neck 

 to the loins, was double. There were also two hearts, one on each side the 

 thorax. The left heart the larger. And two pair of lungs ; one infolding -each 

 heart. Those in the left side were blackish ; the other looked well. The 

 mediastinum parted the two hearts from each other. The aorta and vena cava, 



