432 Mr. H. Prater on the Anti-iitflammable and 



depth, in great part, exceeds Persian side of the gulf, the 

 forty fathoms, along the whole depth, in great part, exceeds 

 of the Arabian or western and 40 fathoms, along the whole 

 southern side it varies from of the Arabian or north-west- 

 twenty fathoms to shallows ern side, it varies from 16 fa- 

 whicli are unnavigable, and thoms to shallows which are 

 which, to all appearance, will unnavigable, and which to all 

 soon rise altogether above the appearances, will soon rise al- 

 level of the sea." — Phil. Mag. together above the level of the 

 for July 1835, vol. vii. p. 43. sea." — Ainsworth, p. 141. 



I am ready to believe that the omission of the reference to 

 me has been unintentional ; still, in justice to myself, I am 

 bound to allude to the fact. 



I am, Gentlemen, yours, &c., 

 Leipzig, March 23, 1839. CharlES T. Beke. 



LXV. Observations oji the Anti- Inflammable and Anti-Dry- 

 Rot Powers of the Subcarbo7iate of Soda and other Salts, 

 By Horatio Prater, Esq.* 

 ]Y/f GAY-LUSSAC some years ago stated that if paper 

 ■^ ^ • be dipped in a solution of phosphate of ammonia and 

 dried, the iiiflammability\ of such paper is destroyed. 



I was induced by this observation in the winter of 1836 to 

 prosecute this subject ; and at that period, calico, wood and 

 paper were kept immersed in various saline solutions for days 

 together, in order to ascertain the comparative energy of 

 such solutions in destroying the property of inflammability. 

 As the object of these experiments was altogether practical, 

 those saline solutions only were tried which could be obtain- 

 ed at a sufficiently low rate for general use. Accordingly, for 

 the phosphate of ammonia proposed by M. Gay-Lussac, the 

 muriate was substituted ; and this was found to have the 

 greatest effect in destroying the inflammable property of 

 wood, calico, or paper. Wood should remain a week or ten 

 days immersed in a saturated solution of it; for calico and linen 

 twenty minutes, and for paper two or three hours at furthest 

 is sufficient:}:. If either of these be dried after such immer- 

 • Communicated by the Author. 



t By this we mean that the paper cannot now be made to consume ivilh 

 flame. Held in a burning candle, it is still immediate/^ carbonized and 

 gradically dissipated. 



X Some very thick paper was rendered uninflammable by immersion for 

 six hours. Of course the time required in all these cases must vary with 

 the thickness of the materials : but when we are sure that the solution has 

 tlioroiighly permeated the texture, we should take it out, as this may be 

 slightly injured by remaining exposed to the action too long. These ob- 

 servations in regard to the time of immersion apply equally to subcar- 

 bonate of soda, 



