% File src/library/datasets/man/Formaldehyde.Rd
% Part of the R package, https://www.R-project.org
% Copyright 1995-2025 R Core Team
% Distributed under GPL 2 or later

\name{Formaldehyde}
\docType{data}
\alias{Formaldehyde}
\title{Determination of Formaldehyde}
\description{
  These data are from a chemical experiment to prepare a standard curve
  for the determination of formaldehyde by the addition of chromotropic
  acid and concentrated sulphuric acid and the reading of the resulting
  purple color on a spectrophotometer.
}
\usage{Formaldehyde}
\format{
  A data frame with 6 observations on 2 variables.
  \tabular{rlll}{
    [,1] \tab \code{carb}   \tab numeric \tab Carbohydrate (ml) \cr
    [,2] \tab \code{optden} \tab numeric \tab Optical Density
  }
}
\source{
  \bibshow{R:Bennett+Franklin:1954}
}
\references{
  \bibshow{R:McNeil:1977}
}
\examples{
require(stats); require(graphics)
plot(optden ~ carb, data = Formaldehyde,
     xlab = "Carbohydrate (ml)", ylab = "Optical Density",
     main = "Formaldehyde data", col = 4, las = 1)
abline(fm1 <- lm(optden ~ carb, data = Formaldehyde))
summary(fm1)
opar <- par(mfrow = c(2, 2), oma = c(0, 0, 1.1, 0))
plot(fm1)
par(opar)
}
\keyword{datasets}
