Evolution of human colour vision that are found between 450 and 625. Individuals with various forms of colour blindness such as deuteranopia and protanopia are missing human middle wavelength sensitive or long wavelength sensitive opsins. Their minimum wavelength differences are <5 but only at around 500. Protanopes, who are missing long wavelength sensitive cones, are unable to distinguish between colours in the green-yellow-red section of the electromagnetic spectrum. They find yellow, red and orange colours to have much lower brightness when compared to a trichromat. The dimming of these colours can result in confusion in many cases, such as when attempting to identify red traffic
What to the Slave Is the Fourth of July? What to the Slave Is the Fourth of July? "What to the Slave Is the Fourth of July?" is the title now given to a speech by Frederick Douglass delivered on July 5, 1852, in Corinthian Hall, Rochester, New York, addressing the Rochester Ladies' Anti-Slavery Society. The speech is perhaps the most widely known of all of Frederick Douglass' writings save his autobiographies. Many copies of one section of it, beginning in para. 32, have been circulated online. Due to this and the variant titles given to it in various places, and the fact that it is called a July