“Carroll Led World in Wormseed Oil Production”

Carroll County Times article for 19 November 2000
by Jay A. Graybeal

Carroll County’s rich agricultural history includes an interesting chapter about the production of wormseed oil, a natural vermifuge.  By the late nineteenth century farmers in the southern part of the county were cultivating wormseed plants.  They eventually led the world in the production of the valuable oil. The November 27, 1925 issue of the Democratic Advocate newspaper included an article about the Klee Milling Co., then the county’s leading producer:

“Wormseed oil, a product of Carroll county, has the world for its market.  It is sold from the tip of South America all through European countries, to the coast of China and Japan.

It has curative properties for hook-worm in humans.  Also used to treat ringworm in swine.

Wormseed oil is obtained from the herb called wormseed.  The oil is separated by means of distillation.  It is not a native of Carroll county or of Maryland.  Carroll county people know nothing of its history, but believe it can be raised in any field which produces corn.

As early as 1890 farmers around about Eldersburg raised wormseed and prepared it for a concern in Ohio, which acted as distributing agent through the Southern United States.

There it was found to be beneficial in the treatment of hookworm.  Afterward the Rockefeller Foundation, in its research work, increased its use in hook-worm, and discovered its value in the treatment of worms in the lower animals.

Today there is raised in Carroll county about 40,000 pounds annually.  The price obtained is from $3 to $7 a pound.  Generally it ranges about $4.50 a pound.  The estimated value of the crop is $175,000, distributed among 175 farmers.

The growing of wormseed presents a number of agricultural troubles.  Early in the spring the seed plant beds are set out.  The plants are kept there until the latter part of May.  Then the plants are about five inches high.  They are replanted in the fields exactly as tomatoes are handled.

It is a ninety day crop.  In September the plant is harvested by a binder.  The only part that is commercial is the cluster of seeds.  Then it is put in shocks and allowed to cure for several days.  The real work of producing the oil from the seeds now begins.  In the early days of the industry the seed was separated from the herb and placed in pots holding about eight gallons.  Water was added and a fire built under the pots.  A soapstone cover had through it a long tin pipe, through which the steam arising from the boiling mass was allowed to cool and condense.  This condensation was caught in a jar, and the oil being lighter arose to the top and was taken off for shipment.

In 1905 John P. and Henry Klee invented a steamtight retort, of about four feet cubical contents, which had a series of pipes through which condensation took place.  In 1900 was established as a basis of purity, a specific gravity of 965 for the oil.  It was thought impossible by the producers to produce this standard.

It was ten years before it was discovered that the specific gravity of 965 could only be produced by the full maturing of the plant.  For years the best figure obtained was 940.  In 1919 by allowing the seed to remain on the plant fifteen days longer, the specific gravity was brought from 940 to 970.

Carroll county growers of wormseed do not fear a surplus.  The demand for the oil has grown from 2,000 pounds in 1914 to 45,000 in 1925.   It is generally produced in lots grown from three to four acres—a sort of a by-product of the farm.  The Klee Milling Company are the largest producers, they growing this year about twenty acres.

The cost of producing wormseed oil according to Henry Klee, is $3.40 a gallon.  He says that the impression that wormseed oil is produced from a wild herb of that name is misleading.  It originated with the wild herb, but today there is no crop in Carroll county that requires more work.

From the time the plants are taken from the seed bed to the field it is a constant struggle to keep them free from weeds.  It has been found that the best results are obtained from cultivation between rows, and cross cultivation is not used at all.

After the distillation of the oil, it is shipped from Carroll county in galvanized steel drums.   The greater part of the product is marketed in New York, but there are distributing agencies in Chicago and Marion, Ohio.

The best market for wormseed oil is found in the Middle West, where many of the shipments are made direct from Eldersburg.

Both England and Germany are consumers, and regular shipments are made to China and Japan.  All of the South American countries are customers, and the Rockefeller Foundation is using a large amount in hookworm treatment of this country.

The distilling process has attracted the attention of travelers along the State roads of Carroll county.  The seeing of more than 100 stills working in daylight raised the question of their production.

The process is almost identical with that of moonshine liquor.   Autoists have come back with wild stories of stills in public places around Eldersburg, but they are stills for the production of the only known cure for hookworm.”