194 On the Constitution of aqueous Ammonia, 



might be expected from the greater volatility and decomposalilily 

 of this salt ; but still according sufficiently well with the above 

 equivalent (or atomic) constitution. 



The experiments with the sulphuric and muriatic acids were 

 several times repeated, so that I have no doubt but we may 

 safely estimate the real alkali in 100 grains of the water of am- 

 monia of O-DOO, to be not less than 25 grains. Sir H. Davy 

 makes it 26, and Mr. Dalton 22*2. 



I am preparing a complete table for every density interme- 

 diate between 0*900 and TOGO. Meanwhile the foUovving rule 

 for ascertaining the proportion of ammonia, will be found con- 

 venient and tolerably correct. Subtract the number denoting 

 the specific gravity of the aqueous ammonia, expressed in three 

 integers, from 997, and divide the remainder by 4 ; the quo- 

 iieiit will be the per centage of alkali. 



Examples. Thus, the density is 945"5. What is the per 

 centage of ammonia ? 



997-945-5 = 51-5;and — = 12-875 = the ammonia in 100 



grains of the water. 



The specific gravity is 971*5. The proportion of the consti- 

 tuents is sought. 



997-971-3 = 25-7; and — = 6-425, for the ammonia; 



and of course 93*575, for the water present. Both these de- 

 terminations are, I believe, very near the proportions as given by 

 experiment. 



Since 75 of water become, in water of ammonia of 0-900, 

 !0U by weight, and 11 I'll by measure ; it is evident, that 6-75 

 in bulk of water, become 10 in bulk of that aqueous ammonia ; 

 for 6-75 : 10 : : 75 : 1 1 1*1 1. A slight typographical error re- 

 quires to be corrected in the second column of the article Am- 

 monia of the Dictionary. " Correcting the first error, vvhere 

 6 is substituted for 9," should be read, " where 6 is substituted 

 for 6-75." 



If we reckon 25 to be the true per centage of alkali in the 

 above water ; and the weight of 100 cubic inches of the gas to 

 be 18 grains, then 75 grains of water combine with 138*&8 cu- 



100 X '") 



bic inches of gas (= — rr~) 5 ^^ ^ grain of water combmes 



with 1*852 cubic inchrs, equivalent to 467*63 grain measures; 

 (= 1-852 X 252*5). Thus I volume of water condenses 467*63 

 volumes of gas, and becomes 1-48 in volume of aqueous ammo- 

 nia of 0"900. And if these 1*48 volumes contain 467*63 of gas, 

 I volume of the water will coutaia 316 of gas. 



We 



