i eee 
‘j Miscellanies. 199 
are all that is necessary to discriminate between the various coloring ma- 
terials used in coloring wine. 
Sulph. alum.andcarb.am. Basic acetate of lead. 
Ordinary red wine, grayish precipitate, bluish gray precipitate. 
Logwood, dark violet, blue. ' 
Brazil wood, rose red, wine red, 
Wild poppy, grayish, dirty gray. 
Recent juice of danewort, bright violet, bluish gray. 
Fermented “ bright violet, beautiful grass green. 
Elder berries, bluish gray, dirty green. 
Privet berries, pale green, dirty green. 
Litmus, rose red, bluish gray. 
When litmus is present in small quantities, it is not indicated by the 
above test; the wine should then be cautiously evaporated to the consis- 
tency of an extract—a small quantity of which is dissolved in a little 
pure water and tested. ‘The sulphate of alumina and carbonate of am- 
monia are not mixed previously, but are added alternately to the wine. 
Osmium, by E. Fremy, (Compt. Rend. Sept. 1844, p. 468.)—In the 
abstracts for this Journal, Vel. xviii, p. 185, Fremy’s method of obtain- 
ing this metal in a state of purity was given; he has since published his 
entire research upon this substance. The atomic weight was determined 
by burning a weighed portion of the metal in oxygen gas, condensing the 
acid formed, and estimating its quantity; it is found to be 99°76, (hydro- 
gen I,) very nearly that given by Berzelius. 
The most interesting compounds described by the author are the os- 
mites, OsO°-+-X. The osmite of potash is the most important of them 
all, and is formed when the osmate is placed in contact with a body hav- 
ing considerable affinity for oxygen. The ease with which the osmite of 
potash is prepared, makes it a convenient method of determining the 
quantity of osmic acid present in a liquid—thus, saturate the osmic acid . 
solution with potash, and add a few drops of alcohol, which determines 
both the formation and precipitation of the osmite; the osmite is then 
washed with alcohol and weighed. The osmite of potash is red, soluble 
in water, completely insoluble in alcohol, crystallizes in ectahedrons, but 
it cannot be crystallized out of water, as that decomposes it; but may be 
obtained in the crystalline form by putting a very alkaline solution of os- 
mate of potash in contact with nitrite of potash, when the osmite forms 
gradually and crystallizes, (crystals contain two atoms of water.) Its so- 
lution in water decomposes tolerably rapidly into osmate of potash and 
deutoxide of osmium. 
The action of ammonia upon a cold solution of the osmite of potash 
is curious, forming a body having for its composition Os O? Az H?, (the 
oxide of osmium in combination with the radical Az H?, that Gay-Lussac 
and Thenard obtained in combination with potassium and sodium.) It 
