much for it, & the truth is I wonder how any man [can] tell what to give, there be so many nice considerations in that matter in all which one has nothing but meere guesse to guide himself by.
A. Why, did you buy it set?
B. What should I doe with it unset?
A. If you bought it set you lost two of the best guides & measures whereby to have known its price, namely the weight and the extent, both which are computable otherwise then by meer guesse; beside the water and colour of the stone as also the clouds icecles & points are somewhat better discerned when you can look round about it, then when you look upon it but as through a window.
B. Well, I was not so wise; but I must needs buy some more diamonds shortly, wherefore pray instruct me if you can.
A. I will & first take notice that the deerness or cheapness of diamonds depends upon two causes, one intrinsec which lyes within the stone it self & the other extrinsec & contingent, such as are[1.] prohibitions to seek for them in the countrys from whence they come.2. When merchants can lay out their money in India to more profit upon other commoditys & therefore doe not bring them.3. When they are bought up on feare of warr to be a subsistence for exiled and obnoxious persons.4. They are deer neer the marriage of some great prince, where great numbers of persons are to put themselves into splendid appearances, for any of theise causes if they be very strong upon any part of the world they operate upon the whole, for if the price of diamonds should considerably rise in Persia, it shal also rise perceivably in England, for the great merchants of Jewels all the world over doe know one another, doe correspond & are partners in most of the considerable pieces & doe use great confederacys & intrigues in the buying & selling them.
twenty-one persons, Petty being another, who were named members of the Council in the second charter of the Royal Society, 1663. Birch, i. 223. The "Dialogue," apparently in Hill's hand, is without title or caption, but it is ascribed by him to Petty and both its method of reasoning and its style of expression confirm the correctness of his ascription. I have followed the suggestion of Dr Bevan in calling the paper "The Dialogue of Diamonds". Bevan, Petty, p. 63.
