366 A BLOWPIPE REAGENT—BOWMAN. 
dry reagents. Grey fumes of mercury are often deposited at 
first but may be changed to yellow and red by touching them 
with the blowpipe flame. Cobalt gives a greenish-brown ccating, 
the brown evanescent and passing into faint green. This fades 
out ultimately. Selenium, Tellurium, and Thallium yield char- 
acteristic coatings with hydriodic acid according to Dr. Haanel, 
but I have never had specimens of them to test for myself. 
Tungsten I tried when at College with potassic iodide solution, 
but had none to test with dry reagents now. Copper, cadmium 
and zine all give white coatings, but the tablets have to be 
blackened to perceive them and then they can only be differentia- 
ted by some wet chemical test, so I have omitted them altogether. 
After writing the above it occurred to me that as hydriodic 
acid is prepared in the laboratory from phosphoric iodide, pos- 
sibly soda-ammonic phosphate, commonly called microcosmice salt, 
or salt of phosphorus, might serve to mix with the crystalline 
potassic iodide. Time did not allow of going over all the tests 
again with this substance, but those that were tried gave most 
satisfactory results. 
This is a most decided improvement as microcosmic salt is 
always present in a blowpipe cabinet. The following are the 
results obtained with this reagent. Arsenic, lead and antimony 
yield good results. Cobalt is better than with ferric sulphate 
and gold is about the same. 
This method with dry potassic iodide and a dry salt, I think I 
am safe in specifying microcosmic salt, has added certainly six 
and probably seven metals to the list of those that can be deter- 
mined by a dry assay. I say probably seven, as I believe that 
practice in manipulation will bring out the result with tin, the 
only one I have failed with. 
Thus a mineralogist fitted out with bottles of borax, carbonate 
of soda, microcosmic salt, and potassic iodide, with his lamp, 
blowpipe, a few plaster tablets, and possibly a few pieces of 
charcoal, can determine twenty-one metals, four non-metals, the 
silicates, nitrates, phosphates, chlorides and alkalies. The only 
two important substances not included are alumina and magnesia, 
