The "tree of life" iconography, representing the history of life, dates from at least the latter half of the 18th century, but evolution as the mechanism providing this bifurcating history of life did not appear until the early 19th century. There was also a shift from the straight line, scala naturae view of change in nature to a more bifurcating or tree-like view. Throughout the 19th century ...

This paper summarises the available information to date on pigments used Portuguese azulejos between late 16th century and beginning of 19th century. Most references cited focus 17th-century tiles, followed by century, whereas there is very little 18th centuries. Regardless chronology, azulejo palette uses cobalt, copper, manganese, iron oxides obtain blue, green, purple, dark brown, respective...

(1.1) (x1 + x 2 2)(y 2 1 + y 2 2) = (x1y1 − x2y2) + (x1y2 + x2y1). There is also an identity like this for a sum of four squares: (x1 + x 2 2 + x 2 3 + x 2 4)(y 2 1 + y 2 2 + y 2 3 + y 2 4) = (x1y1 − x2y2 − x3y3 − x4y4) + (1.2) (x1y2 + x2y1 + x3y4 − x4y3) + (x1y3 + x3y1 − x2y4 + x4y2) + (x1y4 + x4y1 + x2y3 − x3y2). This was discovered by Euler in the 18th century, forgotten, and then rediscover...

The land helix, or snail, has been used in medicine since antiquity and prepared according to several formulations. This historical report traces the understanding of their properties from the time of Hippocrates, who proposed the use of snail mucus against protoccle and Pliny who thought that the snail increased the speed of delivery and was "a sovereign remedy to treat pain related to burns, ...

Although new invasive procedures for the treatment of migraine have evolved during the past decades, the application of invasive procedures for this indication is not new. In this review, the history of non-drug treatments for migraine is discussed. Historical texts by physicians known to have written on headache and migraine (hemicrania), well-known books by physicians from the main historical...

The observation of urine protein as a sign of renal disease is one of the eldest examples in medical history where individual measures are used as diagnostic symptoms. Until the 18th century the uroscopist used his eyes, nose and sometimes taste to come to a diagnostic conclusion. From this early use of urine to establish a diagnosis, qualitative and quantitative chemical and microscopic proced...

Lack of consideration of the complex European scientific scene from the late 18th century to the mid-decades of the 19th century has produced partial and often biased reconstructions of priorities, worries, implicit and explicit philosophical and at times political agendas characterizing the early debates on species. It is the purpose of this paper firstly to critically assess some significant ...

In the 18th century, some medical practitioners considered the main pathological feature of asthma to be the production of mucus. Later, during the 19th century, airway smooth muscle contraction was recognized to be a possible cause of airflow obstruction. However, not until 1840 was the contractility of airway smooth muscle clearly established by Charles J.B. Williams, a famous London physicia...

This paper studies the apparent inconsistency between the evolution of GDP per capita and real wages in pre-industrial Europe. We show that these two measures will diverge when any of the three following factors are present: changes in income distribution, changes in labour supply per capita and changes in relative prices. We propose a methodology for measuring the effects of these three factor...