124 



cal purposes, the author owns that other methods of forming it, be- 

 sides those here suggested, might be contrived : but the general pro- 

 blem, he says, is to combine, in the most intimate manner possible, 

 the greatest quantity of mercury with a given quantity of platina. 

 And he adds, that the principal difficulty in resolving the problem 

 will be to unite such a portion of mercury that the specific gravity 

 of the compound may not exceed 12 ; and that it may be soluble in 

 nitric acid. 



In the course of this inquiry, many instances have occurred which 

 show how much we have yet to learn concerning the nature of mer- 

 cury and platina. Of the former, we know that it is perpetually 

 varying ; and that certain solutions of it will frequently change their 

 state in a few hours : and as to the latter, we are still more in the 

 dark concerning its principal properties. A considerable part of the 

 present paper is taken up in describing some experiments respecting 

 these metals, from which we learn that platina will combine with 

 oxygen, and form a true oxide ; that the affinities of platina differ 

 much from what has generally been stated in the tables ; and that, 

 in general, the whole doctrine of chemical affinities still offers a field 

 for much investigation. The affinities of metals, which are here ex- 

 perimentally demonstrated in several instances, will, no doubt, serve to 

 put us upon our guard concerning the admission of new simple metals, 

 which, on close examination, will often, as in the present case of the 

 palladium, turn out to be combinations of so close a nature as not to 

 be easily decomposed. A great obstacle to the discovery of this de- 

 ception is, no doubt, the little dependence that is to be placed on 

 specific gravities ; since, as we have seen above, a contrary anomaly 

 to that which operates upon platina and mercury may take place in 

 other alloys, which in some cases become as much heavier than the 

 mean as the palladium becomes lighter. In a word, the principal 

 task of modem chemists seems to be to simplify and reduce the im- 

 mense number of supposed elements ; and, by a close observation of 

 nature, to learn from what a small store of primitive materials all 

 that we behold and wonder at has been originally created. 



An Account of the sinking of the Dutch Frigate Ambuscade, of 32 Guns, 

 near the Great Nore ; with the Mode used in recovering her. By 

 Mr. Joseph Whidbey, Master Attendant in Sheerness Dock Yard. 

 Communicated by the Right Hon. Sir Joseph Banks, Bart. K.B. 

 P.R.S. Read April 28, 1803. [Phil. Trans. 1803, p. 321.] 



On the 9th of July 1801, this frigate sailed from Sheerness har- 

 bour with a strong favourable wind. In about thirty minutes she 

 went down by the head, and in less than four minutes more she sunk en- 

 tirely, twenty-two of the crew having perished by the fatal accident, 

 which is ascribed to the hawse-holes being extremely large, low, and 

 carelessly left open ; so that by the crowd of sail the ship bore, they 

 were pressed under water, by which means she filled imperceptibly, 

 and sunk before any preventive means could be applied. 



