Kalamazoo, Jackson, Washtenaw, Lenawee, Ingham, Bay and Muskegon are the leading celery-producing counties; the peppermint district is in the south-west corner of the state; and market gardening is an important industry both in the south-west and in the south-east counties.
Straw-plaiting, malting, brewing, and the cultivation and distillation of lavender and peppermint are carried on.
Owing to the climate other countries are less favoured, although lavender and peppermint are largely cultivated at Mitcham in Surrey, in Hertfordshire and Bedfordshire.
The oil may be given in capsules, or in the form of an emulsion, with or without maltextract, or success may be obtained by adding, to every two drachms of the oil, ten minims of pure ether and a drop of peppermint oil.
Mayer (Ann., 18 93, 2 75, p. 363) obtained azelain ketone, C,H140, a liquid of peppermint odour.
Lavender and peppermint oils of English origin rank as the best qualities.