Arizona weekly enterprise., 1889-04-27
Blow Piping. EEI nIn.

To enable the learner to properly execute the blowpipe tests for silver and gold, he should provide himself with the following apparatus and chemicals: A piece of charcoal; an ordinary jack-knife; clay pipe; 1 ID. Of granulated test lead (cost 9 cts per lb) one-half ID. of borax glass (49 | cts.); one-half lb. of nitric acid (25 | cts.); 1 lb. of bone ash (20 cts) and 3 small glass test tubes, about ) inches long 0 cts. each) besides the blowpipe and candle as described in last weeks article.
 Having learned to blow an uninter- rupted and steady blast of air through the blowpipe and to produce good oxldizing and reducing flames, as per instructions in the last issue, the learner can now proceed to the exc cution of the silver and gold tests as follows
 SILVER TEST.
 Bore small cone shaped hole with the blade of the knife ill the charcoal near the end, about one quarter of an inch in diameter and the same depth Break up an average piece Of the ore to be tested and pulverize 1t finely. Mix this powdered ore well and scoop out little on the point of the knife | blade, about enough to fill one quarter of the hole in the charcoal Then take about the same quantity in bulk of test lead and spread it on top of the powdered ore in the hole and place on top of the test lead, small piece of borax glass, about the size of the head of match. This completes what is called the charges.
 Now hold the charcoal with its charge in the left hand, slightly at an angle and blow pure reducing, or yellow flame, so as to cover the charge with 1t, of not too strong a current of air at first and continue this blast un
 til the charge Is completely melted,
 which requires from l to minutes. Increase the strenth of the same flame
 and keep it up until all of the par
 ticles, or globules of lead, are collected
 in button by themselves and until
 the slag is entirely fluid and free from
 lead. Then direct the point of the
 oxidizing, or blue flame, upon the
 Lu5ton for short time say from one
 to two minutes, so as to get rid of all
 such foreign metals as can be driven
 off in the shape of fumes or gas by 8
 strong heat only, and also, to get rid
 of these metals which are known to gC into the slag. The object of this Is tc obtain pure lead button containing nothing but silver and gold and as
 free as possible from all other metals
 Alter the charge has cooled separate 1t from the charcoal with the point O the knife blade; break the slag of
 from the lead and hammer the leaC
 button until it is free from slag anC such brittle metallic substances a may be found adhering to it. Thi concludes the first operation. Yol l now have lead button containing tn silver and gold and traces of foreigl
 metals which may have existed in tn ore
 7 The next step is to obtain the silve g and gold in metallic state, free iron < lead and all other substances. To d
 this first moissen with water som
 bone ash, so that it will stick togethe
 when pressed between the hands. Fiji
 the els clay y pipe with this damp bone as h and press it into the pipe with tn 4 riIdI.b. so as to form slight depres ' sion or hollow on ti1e surface q tlj bone ash. This hollow is to receiv . the lead button in the next operation T. Dry the bone ash in the pipe by plat a 1,o Mo, o take hold of the pipe stem in the lei hand and direct strong oxidizing C
 blue flame, on the surface of the bon 5 ash and when this is thoroughly hea l. ed, drop the lead button into the ho T. low on top of the pipe. Next, dire( IF a strong oxidizing flame of from , minutes duration on the lead buttol 'O until 1t Is completely melted or fuse o and commences to whirl about, an % allow the point of this blue flame F. play very near the button withol s touching 1t with the point of tE '' fame This is to allow a circulatio le of air to take place, between the poil l. of the flame and the button Cel d tinue this until there is no more a ,a pearance of bright colors on the su ,.o face of the lead button, which will i Is dicate that all of the lead has disa ed peared, leaving the silver and gold e. the form of well rounded and brigl m button. During the operation of dri
 ing off the lead, there are formt as Jumps of oxide of lead, known al litharge, arc md the button. As th
 accumulates the pipe should be i
 clined at an angle so that the buttC O. will seek new and clean spot on Il ', bone ash. In case the litharge tn y has surrounded the button to such " extent that the button cannot to made to leave it, as directed, the opt Tn ton should be stopped and the bl r;- ton allowed to cool, the lead al =, litharge should then be removed wi 'n the point of the knife blade and t oi button separated from the ithars mt replaced in the pipe and the op, ne ation continued until completed II directed above.
 GOLD TEST.
 o We now have the silver and go ~ which the ore may have contain, ne combined in the form of a small b Ic- ton. The next step is to separate he silver from the gold. Clean the b to ton well by rubbing it between t sI paper cards and then drop 1t into ch glass test tube and add from 15 to
 drops of nitric acid. Heat the sal
 gently over the flame of the cand he until the acid boils and the silver Is mt desolved, moving the tube over es flame while heating. The gold if a nd will be found in the form of broF ut ish-black powder which settlers in { or bottom of the tube. Pour off the ely quid acid so as to leave the powder TX the tube and add and pour off pl Ind 1- .l =. 1I II