VOL. 1.3 PfllLOSOPHlCAE TRANSACTIONS. 13^ 



evening the contrary would have happened ; for the moon in that eclipse, be- 

 ginning in the morning, was higher about the end than at the beginning, was 

 nearer us, and consequently must appear larger ; but if the eclipse should hap- 

 pen in the evening, she would be lower at the end, and therefore more dis- 

 tant from us, and consequently appear less. So also in two different places, 

 one having the eclipse in the morning, and the other at noon, the moon must 

 appear larger to him that hath it at noon: and she must likewise appear larger 

 to those who shall have a less elevation of the pole under the same meridian, 

 because the moon will be nearer them. 



A Relation of the [^supposed] Loss of the Method of preparing the 

 Bo?ionian Stone for shining. Anonymous. N" 21, p. 375. 



In this short notice an apprehension is expressed lest the art of preparing 

 and calcining the Bononian stone, so as to possess the property of absorbing 

 and emitting light, should be lost.* 



Description of a Swedish Stone, which affords Sidphur, Vitriol^ Alumy 



and Minium. N' 21, p. 375. 



There is a stone in Sweden of a yellow colour, intermixed with streaks of 

 white, as if composed of gold and silver, and very heavy. It is found in firm 

 rocks, and runs in veins, upon which they lay wood, and set it on fire. When 

 the stone is thus heated they cast water upon it to make it split, and then dig it 

 up with mattocks. This done, they break it into smaller pieces, and put it into 

 iron pots, of the shape represented by fig. 1, pi. 4 ; the mouth of the one going 

 into the other. These they place, the one in the oven upon an iron fork 

 sloping, so that, the stone being melted, it may run into the other, which stands 

 at the mouth of the oven, supported on an iron. The first running of the 

 stone is sulphur. 



The remainder of the burned stone is carried out and laid upon a high hill, 

 where it lies exposed to the sun and air for the space of two years ; it then takes 



* The Bolognian stone is a barytic spar (sulphate of baiytes). The art of preparing it so as to be- 

 come phosphorescent (the accidental discovery of an Italian shoemaker) has never been lost, though 

 many have made a great secret of it. The process is very simple. The stone being calcined and 

 pulverized is made into thin cakes with mucilage, which, after being dried, are put upon charcoal 

 and subjected to the heat of a reverberating furnace. In this state, if it be exposed to the sun's rays 

 for a few minutes and immediately afterwards brought into the dark, it will appear luminous. The 

 prepared cakes must be carefully preserved from damp. See Malpighi's obsen^ations on the Bolognian 

 stone in the xiith vol. of the Transactions, and an account of Mr. Canton's metliod of making a phos- 

 phorus that will imbibe and emit light like the Bolognian stone in the Iviiith vol. of the Transactions. 



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