1820.] Memoirs of the Ijiterary Society of Manchester. 137 



he is not sure which. On the first supposition, it is com- 

 posed of 



Acid 88.V 



Lime 11^ 



100 

 On the second, 



Acid 92 



Lime 8 



100 



According to the relative weights of the atoms of lime and 

 phosphoric acid, the former of these numbers would indicate a 

 hexaphosphate ; the second an ennea phosphate ; but in none of 

 my experiments, which were very much varied, did I meet with 

 any such compounds. 



Mr. Dalton considers the phosphate of lime in the earth of 

 bones as composed of nearly equal Aveights of acid and base. 



He recognised two phosphates of soda, the phosphate and 

 biphosphate, as had been done by chemists long before his time. 

 From the number which he has pitched on to denote the weight 

 of an atom of soda, he distinguishes these salts by the names of 

 biphosphate and quadriphosphate. The following table gives 

 JMr. Dalton's analysis of some other phosphates : 



Acid. 



Phosphate of barytes 100 + 297 barytes. 



Phosphate of strontian 100 + 200 strontian. 



Phosphate of magnesia 100 + 70 magnesia. 



Phosphate of alumina 100 + 64 alumina. 



Mr. Dalton observes, and thinks the observation new, that 

 nitric and muriatic acid decompose phosphate of lime, as well as 

 sulphuric acid. I will just remind him of one fact. In the 

 original process proposed by Scheele for extracting phosphorus 

 from bones, the first step was to decompose the phosphate of 

 lime by means of nitric acid. 



II. Experiments and Observations on the Combinations oj 

 Carbonic Acid and Ammonia. By John Dalton. — This paper 

 was also read in 1813. He begins it by giving an account of the 

 change which carbonate of amnionia undergoes when exposed 

 to the air. One half of the ammonia gradually flies oft", and 

 leaves a bicarbonate of ammonia comparatively fixed, and 

 nearly destitute of smell. I had given an account of this change 

 in the last edition of my System of Chemistry, from my owa 

 experiments, which had been made before 1813. I presume the 

 fact was known to other chemists. When I mentioned it to 

 Dr. Wollaston and to Dr. Marcet, 1 found they were both aware 

 of it. I mention this to show the disadvantage of pubhshing 



