 In 1896 he began his collaboration with Richard Thomas Baker with an investigation into the essential oils of the Sydney peppermint ("Eucalyptus piperita").With Baker working on the botanical side and himself on the chemical, their studies resulted in a remarkable work, "A Research on the Eucalyptus especially in Regard to their Essential Oils" which was published in 1902.A revised edition of this work embodying later researches appeared in 1920.