Discovery history of pulmonary circulation

Until Ibn al-Nafis, the standard explanation of heart anatomy and function was from Galen who believed that blood move from the right ventricle to the left through a series of pores or passageways between the two sides.

In the thirteenth century, Ibn Nafis was practicing physician who studied medicine in Damascus. He was attached to the Mansuri Hospital in Cairo.

In his commentary on Avicenna’s Canon of Medicine, Ibn al-Nafis clearly describes the pulmonary circulation, although there is still reference to blood mixing with air to become ‘purified’.

Ibn al-Nafis clarified all that when he studied the heart lung blood circulation, observed through many surgeries and possibly disection. I

Ibn al-Nafis’ description of the lesser circulation was brought to light in 1924, by Muhyi ad-din at-Tatawi, who found it while examining some Arabic manuscripts in Berlin and presented it before the medical faculty of Freiburg as part of his doctoral thesis.

It wasn’t until 1553, that a clear description of pulmonary circulation was published in the West, in Christianismi Restitutio, written by Michael Servetus (1511-53), a polymath physician and Humanist.
Discovery history of pulmonary circulation

History of decimals

The best achievement of Hindu mathematics is the present decimal position system. The decimal system is very ancient, and so is the position system; but their combination appears in China and then in India, where in the course of time it was gradually imposed upon older non-position systems.

Its first occurrence is on a plate of the year 595, where the date 346 is written in decimal place-value notation. Arabs began using Hindu decimal arithmetic around the seventh century.

The earliest known Arabic treatise on decimal arithmetic Kitab al-hisab al-hindi was written by Al-Khwarizmi around AD 800. Another important early treatise that publicized decimal number, was Iranian mathematician and astronomer, Kushyar ibn Labban’s Kitab fi’ usul hisab al-hind, a leading arithmetic textbook.

Decimal fractions appear for the first time in The Book of Chapters on Indian Arithmetic written in 952 AD in Damascus by Abdul Hassan al-Uqlisi.

Simon Stevin

Toward the end of the sixteenth century Francois Viete (1579) of France and Simon Stevin (1585) of the Netherlands, demonstrated the usefulness of the concepts of decimal fractions for simplifying calculations associated with carrying out lengthy multiplications or divisions.

Not long after that with the introduction of logarithmic concepts in the early seventeenth century, to become clear that decimal fractions could be very useful in navigation, surveying and other practical situations.

Simon Stevin (154801620), a Flemish engineer,is them an usually credited with the introduction of the theory of decimal fractions. In 1585, Stein published a work called La Disme, which is French means The Tenth. In this book he explained his new method of writing fractions.
History of decimals