[ 47 6 ]

platina, in a retort, to which was adapted a recipient. Amoderate heat being applied, the menstruum acted prettybriskly, and red fumes arose in abundance. When abouttwo thirds of the liquor had come over, the action wasscarcely or not at all sensible, though the fire was consider-ably raised. The distilled liquor, which appeared of alight reddish colour, being poured back again into the re-tort, the dissolution begun afresh: the vapour, whichnow came over, was much paler than the first. The co-hobation being repeated four times, the distilled liquorproved paler and paler every time : at length both thefumes and action ceased, though the fire was augmented,and a considerable part of the platina remained undissolved.The solution was therefore poured off, some more of themenstruum added, the distillation and cohobation renewed,and these processes repeated, till all the platina appearedto be taken up, except a little blacklist matter whichseemed to be its impurities. The last portions of the men-struum seeming not to be sufficiently saturated, some moreplatina was added; and after the acid had ceased to act,the remaining platina was dried and weighed, to fee howmuch of it had been dissolved. It was found, that by thisway of application, one ounce of platina was dissolved byeight ounces and a quarter of the menstruum; whichquantity of the menstruum, as appears from the mannerof its preparation, consisted of about four ounces and a.half of strong acid spirit, diluted with three ounces andthree quarters of water ; whereas, when the digestion wasperformed in open vessels, and the fumes suffered to escape,about fourteen ounces of the above menstruum, contain-ing nearly eight ounces of strong acid spirit, were necessa-ry for dissolving one ounce of platina. Platina appears torequire a much greater quantity than gold, and to dissolvefar more difficultly.

4, Marggraf