( 70 ) 



There is another historical investigation of Priestley's, and a very 

 practical at least extensively used application thereof that may be 

 recorded as of interest both to physiologists and medical men, viz., 

 his Directions for impregnating Water with Fixed Air (1772). It may 

 be interesting to have in Priestley's own words his account of this 

 matter obviously, the idea of the original manufacture was purely 

 altruistic the benefit of the health of sailors : 



" It was a little after midsummer, 1767, that I removed f rom Warringtoii to Leeds ; 

 and living, for the first year, in a house that was contiguous to a large common brewery, 

 so good an opportunity produced in me an inclination to make some experiments 011 the 

 fixed air, that was constantly produced in it. One of the first things I did in this 

 brewery was to place shallow vessels of water within the region of fixed air, on the 

 surface of the fermenting vessels ; and having left them all night, I generally found, the next 

 morning, that the water had acquired a very sensible and pleasant impregnation ; and it 

 was with peculiar satisfaction that I first drank of this water, which, I believe was the 

 first of its kind that had ever been tasted by man. 



" Several of my friends who visited me while I lived in that house will remember 

 my taking them into that brewery, and giving them a glass of this Pyrmont water 

 made in their presence. 



"From 1767 to 177 2, I never heard of any method of impregnating water with 

 fixed air but that above mentioned. Being at dinner with the Duke of Northumberland 

 in the spring of the year last-mentioned, his Grace produced a bottle of water distilled 

 by Dr. Irving, for the use of the navy. This water was perfectly sweet, but, like all 

 distilled water, wanted the briskness and spirit of fresh spring water ; when it 

 immediately occurred to me, that I could easily mend that water for the use of the navy, 

 and perhaps supply them with an easy and cheap method of preventing or curing the 

 sea scurvy, viz., by impregnating it with fixed air. For, having been busy about a year 

 before, with my experiments on air, in the course of which I had ascertained the pro- 

 portional quantity of several kinds of air, that given quantities of water could take up, 

 I was at no loss for the method of doing it in general, viz., inverting a jar filled with 

 water, and conveying air into it, from bladders previously filled with air. This scheme 

 I immediately mentioned to the Duke and the company, who all expressed their wishes 

 that I would attend to it, and endeavour to reduce it into practice ; which I promised to do. 



" A few days after this, having occasion to wait on Sir George Savile, I carried 

 with me a bottle of my impregnated water, and told him the use that might be made of 

 it, viz., that of supplying a pleasant and wholesome beverage for seamen, and such as 

 might probably prevent or cure the sea scurvy. Sir George, with that warmth with 

 which he espouses everything that he conceives to be for the public good, insisted upon 

 writing a card immediately to Lord Sandwich, proposing me to introduce me to him as 

 having a proposal for the use of the navy. As I could make no objection, the card was 

 accordingly written, and an answer was presently returned by his Lordship informing 

 us, that he would be glad to see us the next day." 



ANTOINE L. LAVOISIER. 



I 743- I 794- 



OF all the crimes committed during the Keign of Terror, there is 

 none so atrocious, or that lies so heavily on the national con- 

 science, as the execution of Antoine Laurent Lavoisier on the 

 morning of May 9th, 1794. 



