Arthur Hill Hassall's work in public health led to reforms in water purity and to the Food Adulteration Act of 1860 in the UK and subsequent laws against the practice. Woodward may have gotten the title of his book wrong. It might be Food and Its Adulterations. Woodward, this letter's author, was a pioneer in photomicroscopy. Henry, its recipient, was head of the Smithsonian. The history of federal American food quality control begins a decade after this letter was written.
March 9, 1875
Professor J. Henry.
Respectfully returned. Beautiful plates of the microscopical appearances of various kinds of milk can be found in the Atlas of the "Cours de Microscop[i]e," of A. Donné, Paris, 1845, Plates XVII, XVIII, and XIX, and very good woodcuts, with an excellent account of the subject, in the article on "Milk and its adulterations," in Arthur Hill, Hasslin [Hassall] "Adulterations Detected," 2nd Edit, London, 1811, p. 205.