8 A Tribute to the Memory of 



ounces of oil of vitriol being found sufficient for the decomposi- 

 tion of 120 gallons of lime water*. The only difficulty was in 

 the mode of applying the gas on a large scale ; but this was 

 overcome by the contrivance of an apparatus, which Mr. Henry 

 described in a pamphlet dedicated to the Lords of the Admiralty. 

 The proposal, in consequence of the zealous personal exertions 

 of Mr. Wedgwood, who was then in London, met with due atten- 

 tion from the Commissioners for victualling His Majesty's ships. 

 The chief obstacle to its adoption in the Navy was an apprehen- 

 sion, probably well grounded, that persons would scarcely be 

 found on ship-board, possessing sufficient skill for conducting the 

 process successfully. Since that time, the preservation of water 

 at sea has been accomplished by the simple expedient of stowing 

 it in vessels constructed or lined with some substance, which is 

 not capable of impregnating water with any putrescible ingre- 

 dient ; for good spring water, it is well known, contains essen- 

 tially nothing that disposes it to putrefaction. 



The philosophical pursuits of Mr. Henry, not long after this 

 period, received an additional stimulus by the establishment of 

 the Society to which these pages are addressed, and by his 

 anxious desire to fulfil his duties as a member of it. To him, 

 on its being first regularly organized in the winter of 1781, was 

 confided the office of one of the Secretaries. At a subsequent 

 period, he was advanced to the station of Vice-President, and 

 in the year 1807, on the vacancy occasioned by the death of the 

 Rev. George Walker, F. R. S., he received from the Society, 

 and retained during the rest of his life, the highest dignity 

 which it has to bestow. 



The "Memoirs of Albert de Haller," vfhich were published by 

 Mr. Henry in 1783, and dedicated to this Society, were derived 

 pai'tly from a French JEloge, and partly from information commu- 

 nicated by the late Dr. Foart Simmons. A more complete view 



* The water, however, for which these proportions were sufficient, 

 could not have been completely charged with lime, for fully saturated liine- 

 water would have required for decomposition nearly three times that 

 quantity of chalk and oil of vitriol. 



