James Logan and His Maize Experiments

“Milium Indicum maximum Maiz dictum, sive Fromentum Indicum, vel Turicum aliquorum, Indian or Turckey Whest.” John Parkinson, Theatrum Botanicum, London: 1640, Tribe 12, Chapt. 24, p. 1138 Bartram’s Garden, The John Bartram Association Dr. Philip George book collection.

Passages taken from “Jogging Along With and Without James Logan: Early Plant Science in Philadelphia” by Joel T. Fry, presented at the conference “James Logan and the Networks of Atlantic Culture and Politics, 1699-1751” Philadelphia, PA, 18-20 September 2014. Sponsored by the McNeil Center for Early American Studies, Library Company of Philadelphia, Historical Society of Pennsylvania, and Stenton.

James Logan (1674-1751) was one of the leading colonial figures in early 18th century Pennsylvania – significant as a political, economic, and cultural actor. Logan has also been frequently cited as a distinguished scientist or a botanist, in recognition of a single set of backyard experiments on the pollination of maize or Indian corn that he documented beginning in 1727. Shortly after those experiments, in the middle of the decade of the 1730s Logan was mentoring John Bartram, providing access to books of the old and new standard references in botany, microscopes, and scientific equipment. Logan shared a copy of the first edition of Linnaeus’ revolutionary work, Systema Naturae with Bartram in 1736, introducing the new Linnaean taxonomy to Bartram as it was fresh off the press. Logan, in his only letter to Linnaeus in Oct. 1738 (in Latin), admitted that he was not himself a botanist, but instead praised his friend John Bartram.

Logan’s experiments would seem to be a good example of Baconian or Newtonian science—a simple, yet elegant, empirical demonstration that was easy to explain and easy to repeat. The choice of Indian corn or maize as the subject was perceptive—maize is large and fast growing, with curious flowers and exceptionally large male and female flower parts, separated a good distance along the stalk. (And maize was perhaps one of the most characteristic, new “American” plants then in wide cultivation in the North American colonies and Europe.) Logan’s simple experiments with maize seem to have been replicated by many over the years, and could still stand as a good project for an elementary school science fair. But on close examination it isn’t clear that Logan knew what he was demonstrating or that he proved what he claimed. And at least some of Logan’s contemporaries were not particularly convinced that his demonstration was new or brilliant.

Logan maize experiments came following a reading over the winter 1726-1727 of William Wollaston, The Religion of Nature Delineated (multiple editions 1722-1726) on “Semina primaria Animalium” or “true male seed”; and Richard Bradley, New improvements of planting and gardening (1717-with multiple editions), which presented what to Logan was a new idea: “that all plants have their male as well as female seed”. Logan was excited by the potential metaphysical, theological, and ontological significance of this:

the first Seeds, the true Essences of all beings exist (perhaps ab origine) perfectly formed in the air & other parts of our Globe, that they are received by the Male in Depositories, fitted for them and there prepared with a proper apparatus to be transmitted into the ffemale.[1]

Logan probably began experiments with maize in the spring of 1727, in the back garden of his Philadelphia city house on 2nd Street. And he may have continued the experiments over more than one year—although his written account was summarized as one season. Logan wrote letters to Bristol—to his brother Dr. William Logan, to botanist Thomas Goldney, and others in fall 1727, describing the premises of his maize experiments in some detail. He suggesting they be repeated by his friends in England—“there can scarce be found a finer Diversion in nature than to discover and view the various appartus for this kind of Generation.”[2] The detail of the fall 1727 letters suggest some experiments with maize had already taken place, but perhaps could also be interpreted as a form of “thought experiment,” planned but not yet undertaken.

Logan’s maize experiments have long been interpreted as botanical science, but many of his early enthusiastic letters about this project of “Philosophical Inquiry” suggest it was much more metaphysical and theological principles that Logan was attempting to demonstrate, with the hope that it “…might lead me to believe, tht the true Seeds of all productions or the beings themselves exist somewhere else before they are cloathed with a visible corporeity.”[3]

A letter by Logan in March 1728 found him troubled: “to find Sir Iasac’s opinion was that the animal is in the ovum, for if the new discovery of the male seed in vegetables universally holds, I cannot believe but it will amount almost to a Demonstration that the cause is otherwise.”[4] Logan’s excitement, that he might disprove Newton, and demonstrate the primacy of the male in generation seems to be the point of his decade-long effort to get his maize experiments published. In every version of Logan’s description of his maize experiments, he hoped to demonstrate that unincorporated beings—plants and animals—floated through the air (presumably sourced from a divine being or angels?), and were incorporated solely through the male farina or “seed” as living beings and then grown to maturity in female vessels. This was perhaps an attractive theology for an 18th c. Quaker, but not really very accurate botany or natural science.

When one of Logan’s early letters on his experiments, from November 12, 1734, was first read before the Royal Society by Collinson January 23, 1735, it was summarized in the “Journal Book” of the Royal Society as an argument that life arose from a fundamental animalcule from the air transmitted by the male:

…Animalculum or Embryos of either Plants or Animals were not contained within themselves, but in the Air. And then proceeds to show how by a certain sort of Attraction they are gathered by the Farina or seed of the one sex, and carried into the Ovary of the other.[5]

In a November 20, 1735 letter Logan prepared another, less speculative summary of his maize experiments for Collinson, which was read to the Royal Society in early 1736 and published in the Philosophical Transaction as “Some Experiments concerning the Impregnation of the Seeds of Plants, by James Logan, Esq.”[6] With each written presentation, Logan described the same maize experiments, but somewhat altered what the experiments demonstrated. But through every version Logan’s underlying thesis remained oddly not scientific, but philosophical—a restatement of an ancient philosophical argument that “the Seeds of all Things were in the Air.”

The version of the experiments published in 1736 claimed less, and restrained Logan’s sprawling metaphysical theory. Logan included a short preface to establish that belief in plant sexuality was already commonplace: “As the Notion of a Male Seed, or the Farina Fœcundans in Vegetables is now very common, I shall not trouble you with any Observations concerning it.” Logan then limited the outcome of his experiments to a simple argument that his work disproved similar research on maize by the French apothecary and botanist Claude Joseph Geoffroy (1685- 1752) published in 1711. Geoffroy apparently claimed that maize could sometimes produce seed grown to their full size without being pollenated.[7] Logan’s final version of his maize experiments, enlarged as a Latin essay, dated “Philadelphiæ. 1737” was published in Leiden in 1739 with the assistance of the botanist Gronovius, under the title Experimenta et Meletemata de plantarum generatione. This was later translated into English by John Fothergill, and printed with facing Latin and English text in London in 1747, under the English title: Experiments and Considerations on the Generation of Plants.[8] In the extended Latin essay, Logan returned to his overt belief in “the true seminal Principle” that the “impregnating Male dust” plucked plant (or animal) existence “out of the Air this little Seed or Plant, præexistant and completely formed.” In the female part “we find nothing in the Ova before Impregnation, except a kind of liquid Substance.”

Modern assessments of Logan’s experiments have uniformly ignored his real thesis, and reached the obvious modern conclusion that the maize experiments demonstrated the male and female character of flowers—and that both male and female contributions (or genetic material in modern understanding) were necessary for reproduction. But that view was not Logan’s theory or what he thought he had proved. From his earliest letters on the maize experiments in 1727 he had maintained a certain belief that his experiments proved pre-existent essences were floating in the ether and were transmitted solely by the male principle or farina of the plant.

When Logan extended his examinations into plants beyond maize he found complexity and variability which confused or perhaps contradicted his beliefs. Not all plants disperse pollen into the air like maize, and Logan had not conceived of insect facilitated pollination. His attempts to integrate his (and perhaps Bartram’s) further close observations of the flowers of other plant families actually weakened his theory of “the true seminal Principle”. The middle section of his Latin essay provides evidence that Logan had been reading widely in the standard works on sex in plants, but he had difficulty integrating the results of his reading and observations with his pet theory. And in spite of the fact that Logan and Bartram had been reading Linnaeus’ Systema naturae as early as the summer of 1736 no trace of Linnaeus’ new system or any reference to Linnaeus as an author appeared in Logan’s Latin essay or English translation.

Perhaps most telling, Logan’s essay ended with a series of classical citations, calling on Anaxagoras, Varro, and Theophrastus who taught that “the Seeds of all Things were in the Air, and descended from thence” as support. Logan anticipated there would be something like a Copernican revolution to restore the true doctrine from antiquity, and that his “Hypothesis concerning Generation will be readily adopted by Posterity.” In this light, Logan’s experiments and arguments read more like renaissance humanism than 18th century science—perhaps fitting considering Logan’s interest in classical books and philosophy.


[1] James Logan, Philadelphia to Dr. William Logan, Bristol, September 25, 1727. HSP, Letter Books of James Logan, Vol. III, Section A, p. 41; quoted in Lokken, “Scientific Papers of J. Logan.” p. 76-77.

[2] James Logan, Philadelphia to Thomas Goldney, Bristol, November 20, 1727. HSP, Letter Books of James Logan, Vol. III, Section A, p. 43. Lokken, “Scientific Papers of J. Logan,” p. 77-78.

[3] Ibid.

[4] James Logan to Col. Burnet, March 10, 1728[?].HSP, Letter Books of James Logan, Vol. III, Section C, p. 191. Lokken, “Scientific Papers of J. Logan,” p. 78-79.

[5] 1 Royal Society Journal Book, 16, p. 70-74; Royal Society Letter Book, 21, p. 241-266. Quoted in part by Stearns, Science in the British Colonies, p. 537-538. Logan’s first letter to Peter Collinson on the maize experiments seems to date to November 12, 1734 and was read by Collinson before the Royal Society, January 23, 1735, but never published. This earlier 1734 letter and the first presentation of Logan’s maize experiments to the Royal Society in 1735 was not mentioned in Lokken, “Scientific Papers of J. Logan”.

[6] “VI. Some Experiments concerning the Impregnation of the Seeds of Plants, by James Logan, Esq; Communicated in a Letter from Him to Mr. Peter Collinson, F. R. S.” Philosophical Transactions of the Royal Society, vol. 39, no. 440 (1736), p. 192-195.

[7] Logan only knew of Geoffroy from a transcription of his research in Philip Miller’s Gardener’s Dictionary, and may have largely misinterpreted Geoffroy’s conclusions. Geoffroy’s experiments with maize were similar to Logan’s and included removing the male tassels. They were reported to the Académie Royale des Sciences in 1711.

[8] Fothergill only translated and re-published the “Generation” essay from the 1739 pamphlet. The Latin “Meletemata” was translated as “Considerations” on the title page of the essay, but as “Reflections” on the first page of the essay.

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