The air pump and electrical machines are objects to be feared because they represent the enlightenment and advancement in collective intelligence, the tendency to question and philosophize, and curiosity, all of which would disrupt the status quo that governments and religions have set into place. Joseph Priestly first isolated oxygen and developed theories for its importance, recognizing the role of gases within the air (Johnson, 1168)*. The History of Corruptions of Christianity by Priestley was an example of an intellectual work that criticized the institution of religion and the flaws that it had built up over the centuries that arose during the 1780s, in the midst of the Enlightenment period. This work stirred great controversy and was remarked and/or aided by notable figures such as Thomas Jefferson and Ben Franklin (Johnson, 1916, 1955, 1999). This was enough to cause riots that burned down a church in anger toward him, requiring intervention by British troops to disperse the crowd. It had profound ripples through British society, and many became sympathetic to his beliefs (Johnson, 2087-2177). The progress of science and radical ideas discovered by it often go against the narrative of the institutions of the day, and threaten to undermine the visage of truth and authority these entities hold.
I would say his work is relevant today because his perspective applies to modern developments, in particular, his work on gaseous elements in air is not unlike the ongoing battle for climate change and the fight to vaccinate our population. Though scientifically supported by evidence and with much research done, a disturbing amount of the public and a critically unacceptable amount of people in varying positions of power refuse to acknowledge the truth and will stick their heads in the sand like ostriches. Progress, and the very well-being of humanity as a whole is threatened by this regressive attitude. A well rounded information network with a strong foundation was important to Priestly, as was the knowledge that his findings would be tangled in and have strong implications for politics and society (Johnson, 2593). In this day and age, the dissemination of knowledge, correct, factual knowledge, is more important than ever, as is freedom of speech.
*Note E-book for some reason breaks things down into three thousand sections with multiple in one page, and refuses to number those pages. I used the section number it gave me instead.