In the early eighteenth century, the argument about the nature of light had turned the scientific community into divided camps that fought vigorously over the validity of their favorite theories. One group of scientists, who subscribed to the wave theory, centered their arguments on the discoveries of Dutchman Christiaan Huygens. The opposing camp cited Sir Isaac Newton's prism experiments as proof that light traveled as a shower of particles, each proceeding in a straight line until it was refracted, absorbed, reflected, diffracted or disturbed in some other manner. Although Newton, himself, appeared to have some doubt about his corpuscular theory on the nature of light, his prestige in the scientific community held so much weight that his advocates ignored all other evidence during their ferocious battles.
Huygens' theory of light refraction, based on the concept of the wave-like nature of light, held that the velocity of light in any substance was inversely proportion to its refractive index. In other words, Huygens postulated that the more light was "bent" or refracted by a substance, the slower it would move while traversing across that substance. His followers concluded that if light were composed of a stream of particles, then the opposite effect would occur because light entering a denser medium would be attracted by molecules in the medium and experience an increase, rather than a decrease, in speed. Although the perfect solution to this argument would be to measure the speed of light in different substances, air and glass for example, the devices of the period were not up to the task. Light appeared to move at the same speed regardless of the material through which it passed. Over 150 years passed before the speed of light could be measured with a high enough accuracy to prove that the Huygens theory was correct.
Despite the highly regarded reputation of Sir Isaac Newton, a number of prominent scientists in the early 1700s did not agree with his corpuscular theory. Some argued that if light consisted of particles, then when two beams are crossed, some of the particles would collide with each other to produce a deviation in the light beams. Obviously, this is not the case, so they concluded that light must not be composed of individual particles.