#####   R-code for making Figure 2.8

	dat  <- read.table("soil.dat",header=F)
	x    <- dat$V2

	postscript("fig28.ps",width=6.5,height=3.5,horizontal=F)

	par(mfrow=c(1,2), mar=c(4,4,1,1))

	hist(x, breaks=c(0,0.25,0.5,0.75,1,1.25,1.5,1.75,2,2.25,
	     2.5,2.75,3,3.25,3.5,3.75), freq=T, right=F,
	     xlab=expression(SiO[2]),mgp=c(2,1,0),cex=0.8,main="")
	title(xlab="(a)")

	hist(x, breaks=c(0,0.25,0.5,0.75,1,3.75), freq=T, right=F,
	     xlab=expression(SiO[2]),mgp=c(2,1,0),cex=0.8,main="")
	title(xlab="(b)")

	graphics.off()