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The disease killed an estimated 400,000 Europeans annually during the 19th century and one-third of all the blindness of that time was caused by smallpox. 20 to 60% of all the people that were infected died and 80% of all the children with the infection also died. It caused also many deaths in the 20th century, over 300–500 million.
However, large numbers of silkworms began dying from diseases and the French government asked Pasteur to investigate the problem. [56] Pasture connected the disease in silk worms known as pébrine to the parasite Nosema bombycis. The other disease called flacherie caused silkworms to become dark brown. Pébrine was thought to be a form of ...
Parchment is also extremely affected by its environment and changes in humidity, which can cause buckling. Books with parchment pages were bound with strong wooden boards and clamped tightly shut by metal (often brass) clasps or leather straps; [20] this acted to keep the pages pressed flat despite humidity changes. Such metal fittings ...
Changes in relative humidity can cause parchment to change shape, especially if movement is restrained by a frame or mount at certain parts of the object, which leads to uneven distortion. This distortion can result in cockling and destabilization of any pigments affixed to the parchment. [11] Low humidity levels can cause parchment to ...
A representation by Robert Seymour of the cholera epidemic depicts the spread of the disease in the form of poisonous air.. The miasma theory was the predominant theory of disease transmission before the germ theory took hold towards the end of the 19th century; it is no longer accepted as a correct explanation for disease by the scientific community.
Although the influenza virus that caused the 1918–1919 influenza pandemic was not discovered until the 1930s, the descriptions of the disease and subsequent research has proved it was to blame. [47] The pandemic killed 40–50 million people in less than a year, [48] but the proof that it was caused by a virus was not obtained until 1933. [49]
The Broad Street cholera outbreak (or Golden Square outbreak) was a severe outbreak of cholera that occurred in 1854 near Broad Street (now Broadwick Street) in Soho, London, England, and occurred during the 1846–1860 cholera pandemic happening worldwide.
Studies indicate that lead was very prominent in Roman beverages. This is mostly due to the lead-based storage containers that were popular during the time. [6] Some scholars speculate that the levels of alcohol consumed on a daily basis were more to blame for the health ailments of the aristocrats of Rome, with the average consumption rate being approximately 3 bottles of wine a day. [6]