Purple finch There are two subspecies of the purple finch, "H. p. purpureus" and "H. p. californicus". "H. p. californicus" was identified by Spencer F. Baird in 1858. It differs from the nominate subspecies in that it has a longer tail and shorter wings. The plumage of both males and females is darker, and the coloration of the females is more greenish. The bill of "C. p. californicus" is also longer than that of the nominate subspecies. Adults have a short forked brown tail and brown wings and are about in length and weigh . Adult males are raspberry red on the
Metacresol purple CO dissolves as CO is acidic. In chemistry, it has two useful indicator ranges: Metacresol purple Metacresol purple or m"-cresol purple, also called m"-cresolsulfonphthalein is a triarylmethane dye and a pH indicator that is used in medicine to detect end-tidal carbon dioxide to ensure successful tracheal intubation in an emergency as the indicator inside a colorimetric carbon dioxide detector. It can be used to measure the pH in subzero temperatures of saline or hypersaline media. In colometric capnography the indicator is incorporated in a matrix that provides a pH just above the indicator's colour change, it undergoes the colour change