In “Dismantling the Divide between Indigenous and Scientific Knowledge,” Arun Agrawal problematized traditional distinctions between “indigenous” and “scientific” or “western” knowledge by arguing that knowledge in general is best studied through its application.  Per Agrawal, knowledge itself is not a thing in itself but something useful that is used. Historian James Secord echoed Agrawal’s point ten years later:
To do real historical work, this perspective [that “communicating is the doing of science” ] needs to be not only explicit but also foundational. This means... eradicating the distinction between the making and the communicating of knowledge. Like Agrawal, Secord situated knowledge within its application. This in itself was not a new step for a historian of science. The historiography of the past few decades reflected the influence of the so-called practice turn. However, Secord articulated the relationship between knowledge and practice a step further, specifying that practice in the form of communication has been both the instantiation of scientific knowledge as well as the act of its creation.
I would like to extrapolate these theories to the creation and circulation of medicinal knowledge. There are several challenges in so doing. Medicinal knowledge and particularly medical practices have often been distinct from “scientific” knowledge, particularly in the early 19th century. Further, medicine in the Western tradition has often carried the dual identity of being both a “theory” and a “practice” – a distinction that has carried more or less weight at different times. Nonetheless, Agrawal’s de-distinction between “scientific” and “indigenous” knowledge might similarly erase the boundary between “scientific” and “medicinal” – each identifies a body of instantiated practices that have been practiced by particular people – in the case of medicine, the healer. When the historian also erases epistemic boundaries between “western” and “indigenous” medicinal practices and instead locates any cultural association to the practitioner, medicine appears, by necessity, linked to the social position of the practitioner.
Such a position may be complicated, such as in Métis communities, social groups in the Northwest territories characterized by their mixed French and indigenous ancestry and modes of living and their social positioning between – but not entirely within – both realms.  My current work examines the medicinal practices and episteme of non-professional Métis practitioners in the Northwest Territories during the 1830s. One such individual was Catharine Ely (1817-1880), nee Goulais/Bissell, born in Sault Ste. Marie in the Michigan territories. Catharine’s mother, Josette Grant, was half-Ojibwe. Her father, Joseph Goulais, was a French-Canadian voyageur.  Catharine grew up in the waning milieu of the fur-trade, a society in which French and later British and American traders, soldiers, and missionaries lived and worked alongside Odawa, Ojibwe (or Chippewa), Assiniboine, and other indigenous peoples. Marriage and child rearing between cultural and racial groups formed a society of Métis families and a “creole” culture. 
Catharine converted to Presbyterianism in 1834 and joined the American Board of Commissioners for Foreign Missions (ABCFM) mission at La Pointe in the Michigan territories. Soon after, Catharine met and married Edmund Ely, a mission teacher from New York. Catharine accompanied Edmund to a mission school at Fond du Lac as helpmate, translator, teacher, and wife. She started a diary several months after her marriage and continued the practice sporadically for three years, from 1835-1839.  Catharine’s diary provides a rare opportunity for the historian to understand one practice of Métis medicine.
Among the eighty or so entries in her diary, several refer to medicine. Catharine noted which therapies she used to treat illness - magnesia, peppermint, “rhubard [sic]”, “salts”, and “pills”. Catharine framed disease with a rationale common to European and American settlers: for example, she described her daughter’s teething as “humours… breaking out.”  While Catharine’s medicinal practices and therapeutic rationale were associated with the episteme and trade networks of settler society, her social interactions indicated her awareness of and interaction with Ojibwe kinship networks and social obligation. Catharine distributed medicines in her husband’s absence; on one occasion, she allowed a distraught neighbor to reside with her “until Mr. E arrived” to settle the matter. Catharine’s deference to her husband’s say in household matters would have been typical in American gender politics, but apparently such deference did not hold while her husband was away. Catharine acted as a “go-between” for Ojibwe and settler society through her work as translator, teacher, and mission worker as well as in her social support and medicinal practice.  Catharine, Métis go-between, instantiated Métis medicine.
Thus far I have met Agrawal’s call to seat knowledge in practice. Can I go further and fulfill Secord’s admonition to locate the creation of Métis medicine in Catharine’s communication of medicinal knowledge? If the reader can accept the social act of practicing medicine as a form of communication, then the theory may hold. A comparative analysis of other Metis practitioners is needed in order to track patterns of application and social mediation. From this single window, the study appears promising. Catharine, go-between, negotiating multiple worlds, drew multiple worlds into her practice of medicine - imported drugs, theories about humors, and patients from both Ojibwe and settler societies. Catharine’s practice, as her identity, negotiated a “middle ground” in the Northwest Territories.
 Arun Agrawal, “Dismantling the Divide between Indigenous and Scientific Knowledge.” Development and Change 26, no. 3 (1995): 413–39.
 Secord is quoting Scott L. Montgomery, The Chicago Guide to Communicating Science (Chicago: University of Chicago Press, 2002)
 James A. Secord, “Knowledge in Transit.” Isis 95, no. 4 (2004): 661.
 I have chosen to use “big-M” Métis to refer to Catharine. For an excellent capitulation of the scholarly controversies and racial and political consequences of using ‘Métis’ versus ’métis’, see Chris Anderson, “Moya `tipimsook (‘the People Who Aren’t Their Own Bosses’): Racialization and the Misrecognition of ‘Métis’ in Upper Great Lakes Ethnohistory.” Ethnohistory 58, no. 1 (2011): 37.
 "Life Memoranda" filled out by Mrs. Catharine Bissell Ely. Excerpt from Keith Widder’s Battle for the Soul: Métis Children Encounter Evangelical Protestants at Mackinaw Mission, 1823-1837 (Ann Arbor, Michigan: MSU Press, 1999), 104.
 Lucy Eldersveld Murphy, “To Live Among Us” in Native Women’s History in Eastern North America before 1900 : A Guide to Research and Writing, ed. Rebecca Murphy and Lucy Eldersveld Murphy (Lincoln: University of Nebraska Press, 2007), 368-414. See also Murphy, “Public Mothers: Native American and Métis Women as Creole Mediators in the Nineteenth-Century Midwest.” Journal of Women’s History 14, no. 4 (2003): 142–66.
 Edmund Franklin Ely, The Ojibwe Journals of Edmund F. Ely, 1833-1849 (Lincoln: University of Nebraska Press, 2012.) Catharine’s diary can be found in Appendix B. It is possible that she wrote more that has not survived.
 Catharine Ely on November 21, 1836, 448.
 The Brokered World: Go-Betweens and Global Intelligence, 1770-1820, ed. Simon Schaffer, Lissa Roberts, Kapil Raj, and James Delbourgo. (Science History Publications Sagamore Beach, MA, 2009), xiv. In their introduction, the editors state that the “go-between” is not “just a passer-by or a simple agent of cross-cultural diffusion, but someone who articulates relationships between disparate worlds or cultures by being able to translate between them.”