C. remark.
The above facts having induced the conclusion that the metal, thus unexpectedly discovered in the ores of tungsten, was tellurium,[73] we were led to search for external characters by which to judge what specimens contained it. The ores from Transylvania, (the only telluric ores with which we are acquainted,) bearing no analogy in appearance or composition to those before us, we were led to inquire whether the tellurium in these latter ores was in combination with tungsten, or merely in mixture. The external characters detailed in part II, tend perhaps to fortify the latter opinion. If we mistake not, we there found a proper ore of tellurium mixed with a proper ore of tungsten, but we have also by chemical means, found tellurium where similar external characters were not apparent. Before the appearance of our next Number, we hope to obtain purer and better specimens. In the mean time we add the following facts.
1. A crystal, and a massive piece of the kind described under part I, and specimens of two varieties of those described under part II, were digested in nitro-muriatic acid.
2. Both oxyd of tungsten, and oxyd of tellurium were obtained from all of them.
3. Many specimens have been examined which have afforded tungsten only, and no tellurium.
At a convenient time, it is hoped that a more complete examination of this subject may be presented to the public.
In the mean time, we may submit to mineralogists and chemists, whether if this is not a new mineral, it is not at least a new association of two minerals before known. It has not been forgotten that gold and silver are frequently combined with tellurium: neither of them has, however, been discovered, (although sought after by proper tests) during the above trials.
Yale College, March, 1819.