It is only in "tall talk"(or in advertisements) that any human preparation, elementary or not, can be spoken of as chemisch rein.
Solar Chemistry, Nature, Volume XXIV, October 21, 1881 (p. 582)
It is only in "tall talk"(or in advertisements) that any human preparation, elementary or not, can be spoken of as chemisch rein.
Solar Chemistry, Nature, Volume XXIV, October 21, 1881 (p. 582)