[ 53 ° 1

3. One ounce of platina and four of copper, treated inthe same manner, united without loss into a pretty toughcompound, which bore to be considerably flattened, cutwith a chisel, and bent almost double before it cracked.Internally it looked of a fine texture, and of a very palecopper colour.

4. A mixture of one ounce of platina and five of copperstretched somewhat more easily under the hammer thanthe preceding, and appeared of a redder colour.

5. Upon increasing the copper to eight times the quan-tity of the platina, the compound proved sufficientlytough, broke difficultly, and hammered well. It wasmuch harder than copper, and of a paler colour.

6. A mixture of one part of platina and twelve of cop-per was somewhat more easily extended under the hammerthan the preceding, and proved softer to the file. It stucka little in the teeth of the file, which the compositions witha greater proportion of platina did not.

7. A mixture of one part of platina and twenty-five ofcopper was still somewhat paler coloured than pure copper,and considerably harder and stiffer, though very malleable.On increasing the copper a little further, the mixture con-tinued somewhat harder than the copper by itself, and ap-peared of a fine rose colour.

8. In the foregoing fusions, though in general no fluxwas made use of, there was scarcely any loss of weight, ex-cept in No. 1, where the large proportion of platina re-quired the fire to be raised to a violent degree. This seemsowing in great measure to the platina preventing the scori-fication os the copper: for on melting pure copper, a greatnumber of times, both with and without fluxes, there wasconstantly some loss.

9. The mixtures with large proportions of platina are

difficultly extended under the hammer when cold, and

when