There are a number of scholarly works related to race and medicine, including slavery.  Below is a small selection, but please dive into the Syllabus: A History of Anti-Black Racism in Medicine, published by the African American Intellectual History Society (AAIHS), and this guide produced by the Cushing/Whitney Medical Library, which includes contemporary and historical sources.

This is the search box that appears on the Yale University Library home page. Use Quicksearch and enter search terms in the box to get started searching. Don't worry about being too precise at first; you can easily narrow down your results later by clicking on the results and using the choices on the left hand side. 
 

In your results screen, you'll notice that there is a Books+ column on the left, and an Articles+ column on the right, with "View and filter all...results."  Click on the "View and filter..." which will take you into a new screen where you can filter down the many results you get using options (facets) on the left.  Many of the articles in the Articles+ results are fully available online to the Yale community.

Title page from A Narrative of the most remarkable Particulars in the Life of James Albert Ukawsaw Gronniosaw, an African Prince (1790)

Do you know that you can find primary sources on Google Books?
Here are the steps!

1. Go to Google Books.
2. Search for your term (for example, slavery)
3. In your results screen, you'll see "Any time" just under the search bar, but before the results.
4. In the "Any time" tab, click "Custom Range," and put in the time period you want.
5. Once you click on a book, you should see options like "read for free" and "download PDF"

Be aware that books before 1923 are more likely to be fully available online, because of U.S. Copyright law.  Libraries digitized many of their books before 1923.  After 1923, you may find government publications fully online or previews of certain books.

Don't forget to use Google Scholar for articles, which you can also narrow down to certain dates.  And make sure you are logged into Yale's VPN, as Google Scholar connects to our VPN to give you access to articles.