Dr. Arthur H. Hassall examines ground coffee…

Dr. Arthur H. Hassall examines ground coffee through the microscope in 1850.

Eminent chemists had previously found great difficulty in establishing any satisfactory chemical distinction between coffee, chicory and other adulterants of coffee; the microscope immediately shows the structural difference of the particles, however small.

The results of Hassall's examinations are embodied in a paper that is read before the Botanical Society of London and is reported in The Times, 1850.

A paper on the microscopic examination of sugar, showing the presence in that article of innumerable living mites, follows and attracts much attention.

Hassall is in consequence commissioned by Thomas Wakley (1795-1862), the owner of the Lancet, to extend his examination to other articles of food.