Formocresol is a compound consisting of 48.5% formaldehyde, 48.5% cresol, 3% glycerine used in vital pulpotomy of primary teeth and as a temporary intracanal medicament during root canal therapy. Due to high toxicity and availability of alternative solutions and intracanal medicaments, formocresol is considered obsolete in dentistry.
Buckley's solution is a diluted form of formocresol containing 20% formaldehyde which was introduced by Buckley in 1904.
References
Formocresol Wikipedia(Text) CC BY-SA