Showing posts with label Chemistry. Show all posts
Showing posts with label Chemistry. Show all posts

Thursday, November 3, 2022

Roger Bacon's Gunpowder Formula as Revealed in the Harley MS 3528

Roger Bacon is credited with giving one of the earliest compositions for gunpowder. His formula was based a document translating his work some 400 years after his death (Link-> Dee's translation of Bacon's "Epistola de Secretis Operibus Artis et Naturae et de Nullitate Magiae") and a decoding of the anagram in the translated document about 400 more years later (Link-> Hime's "Gunpowder and Ammunition Their Origin and Progress"). The formula received criticism for being unlikely to produce the effects associated with gunpowder. Steele took umbrage to anagram and Hime's interpretation (Link-> “Luru Vopo Vir Can Utriet” in Nature) as it seems an unfair direct criticism of Bacon. Steele presented a similar passage from the Harley MS 3528 that had a less obscured formula, although it still appeared obfuscated. The document in this blog will present the results of investigating and decoding the Harleian MS text to determine a formula (potassium nitrate 68.4%, charcoal 15.8% and sulfur 15.8%) (Link-> Translation of Roger Bacon’s Gunpowder Formula in the Harley Manuscript 3528). 

Bacon believed that some information was so important that it should be kept hidden by cryptic methods. Since he used multiple methods of obfuscation and not a unified method of encryption, any meaning decoded is open to interpretation and will lead to varying opinions. His approach does have as a consequence that enough piecemeal information may be decoded so that a likely but not necessarily complete determination can be made of his intent. The decoding presented is suggestive of his intent and is given so that others may develop it further. The document includes learned and discovered information in the progress to decoding the formula. Some of what was found and its interpretation may be new and useful beyond the simple interpretation of the formula for gunpowder. 

Since scholars, who write in Latin with Medieval script, is far afield from my expertise, there was a significant learning curve. What is presented is subject to all the ills that may result from an untrained novice's foray into a new field. Not all of what was found was included, only that which seems likely to be of value to those with interests in this area.

Friday, August 28, 2020

ASTM D2502 Calculation of Petroleum Oil Molecular Weight

ASTM D2502 has a chart that is used to estimate the molecular weight of a petroleum oil based on two viscosities of the oil.  The chart requires several estimation and interpolations, which can introduce mistakes.  A calculation from mid 1985 using the 2 viscosities is presented (LINK->Calculation of a Petroleum Oil Molecular Weight). The calculated molecular weights compared to the ones determined from the chart have a difference of 2.3 standard deviations.  The calculation is valid for the entire chart. The Microsoft document is available by contacting the author for a Dropbox link.

An Excel workbook (MWPetOilFrom2Vis_VisCalcs.xlsm) and the exported VBA module (MWPetOilFrom2Vis_VisCalcs.bas) are available.  The function MW40_100 calculates the molecular weight from cSt viscosities at 40C and 100C. It converts the viscosities and checks if they are within the bounds of the chart.


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