313 SCIENTIFIC NEWS. 



muriate of potash, a soft green resin, an animal extract, 

 mucilage, and oxigenizable extract. In the berries he 

 Sensible test found as sensible a te6t of acids and alkalis as the infusion 

 alkaUs? aUi of ma11ow flower. By pouring alcohol on the expressed 

 juice of the ripe berry, the purple fluid will be coagulated 

 by the precipitation of the mucilage. This coagulum is to 

 be well washed with the same alcohol, and the tincture fil- 

 tered off. If this tincture be diluted with water till it has 

 no longer any perceptible colour, it will become green with 

 alkalis and red with acids. The purplish colour of this 

 tincture changes to a yellow in time, but it still retains its 

 property of detecting the smallest portion of acid or alkali 

 in water. 

 Potassium ob- Mr. Hitter has obtained the metallic product of potash 



tamed in van- w -^ a | most a |i t ] ie metallic substances yet known, when 

 ous ways. J t ' 



they are employed as the extremity of the negative con- 

 ductor, and always fine and perfect. Arsenic alone pro- 

 duces it of a shining black or blackish colour. He has ob- 

 tained it also by employing charcoal and plumbago as con- 

 ductors: but not with the gray crystallized oxide of man- 

 ganese, which is merely deprived of its oxigen in the pro- 

 Tellur'nim dif- cess. When tellurium was placed in potash as the extre- 

 respects°from Ullt y °^ tne ne g' at ive wire, it did not produce bright metal 

 other metals, of potash, but a brown dirty substance. Mr. Hitter then 

 took tellurium for a negative wire, and immersed it in pure 

 water in which was likewise the positive wire, and immedi- 

 ately streaks of a brown black were produced, which, sepa- 

 rating from the tellurium, fell to the bottom of the water, 

 and from the manner in which they were produced, and the 

 place of their origin, they must have been hidruret of tel- 

 lurium. Thus tellurium produced no metal of potash be- 

 cause it absorbs all the hidrogen itself. The button of 

 tellurium, purified afresh, was employed as a positive wire 

 in pure water ; and, what must excite more astonishment, 

 it remained brilliant, formed no oxide, and gave out a great 

 deal of gas. Thus of eighteen metals subjected to Mr. 

 Ritter's experiments, tellurium is the only one, that pro- 

 duced a hidruret at the negative pole; and the fourth, that 

 with gold, platina, and palladium, gives out gas at the 

 positive pole. Does tellurium then commence a new series 



of 



