Picamar
Picamar is a colorless, hydrocarbon oil extracted from the creosote of beechwood tar with a peculiar odor and bitter taste. It consists of derivatives of pyrogallol. It was discovered by German chemist Carl Reichenbach in the 1830s. Picamar can be used to lubricate machinery.
Chemical and physical properties
The exact composition of picamar is unknown.{{cite book|author=William Gregory|title=Outlines of Chemistry: For the Use of Students|url=https://books.google.com/books?id=u2pEAQAAMAAJ&pg=PA538|year=1851|publisher=H.W. Derby|pages=538}} According to Pastrovich, picamar is a monomethyl ether of propyl-pyrogallol ({{chem|C|10|H|14|O|3}}). However, Gustav Niederist, who obtained an original sample of the oil as prepared by von Reichenbach himself, assigned it a formula of {{chem|C|13|H|18|O|4}}.{{cite book|author=Chemical Society (Great Britain)|title=Journal of the Chemical Society|url=https://books.google.com/books?id=I7w4AQAAMAAJ|year=1883|publisher=The Society|pages=1005–1006}}{{cite book|author=Society of Chemical Industry (Great Britain)|title=Journal of the Society of Chemical Industry|url=https://books.google.com/books?id=PArzAAAAMAAJ|year=1884|publisher=Society of Chemical Industry|page=162}} Picamar is colorless with a peculiar, peppermint-like odor and bitter taste. It is soluble in alcohol and sparingly soluble in water. It has a melting point of {{cvt|545|F|C}}. Picamar reduces the red oxide of mercury to its metallic state.{{cite book|author=William Thomas Brande|title=A Manual of Chemistry|url=https://books.google.com/books?id=eADxV_sWOh8C&pg=PA1169|year=1841|publisher=J.W. Parker|page=1169}} It reacts with nitric acid to become a reddish-brown, greasy substance and can also dissolve camphor, resin, and benzoic acids.{{cite book|author=Leopold Gmelin|title=Hand-book of Chemistry|url=https://books.google.com/books?id=7FUMAQAAIAAJ&pg=PA163-IA2|year=1862|publisher=Cavendish Society|pages=163}}
History
The name "picamar" is derived from the Latin phrase in pice amarum (meaning "bitter principle of tar").{{cite book|author=Richard Dennis Hoblyn|title=A Dictionary of Terms Used in Medicine and the Collateral Sciences|url=https://books.google.com/books?id=Q4IPAAAAYAAJ&pg=PA342|year=1865|publisher=H.C. Lea|page=342}} It was discovered by German chemist Carl Reichenbach in the 1830s as one of the six principles of beechwood tar, along with other substances as capnomor and eupione that were "met with less notice".{{cite web|url=https://www.woodlibrarymuseum.org/library/pdf/S_ACPY.pdf|page=63|title=Letters on Od and Magnetism|year=1851}}
Applications
Picamar is used for greasing machinery and preventing them from rusting.{{cite book|author=Edward Turner|title=Elements of Chemistry: Including the Recent Discoveries and Doctrines of the Science|url=https://books.google.com/books?id=3motAAAAYAAJ&pg=PA874|year=1834|publisher=John Taylor|page=874}}