Chlorine in Peroxide of Manganese, 287 



in minute crystals. The supernatant fluid was poured off, 

 and the crystals washed with a little cold water, which was 

 added to the rest of the fluid. The whole being now diluted, 

 was mixed with a solution of nitrate of silver, and the precipi- 

 tate being allowed to subside, was boiled in a large quantity of 

 ■water to dissolve the sulphate of silver. (The quantity of 

 which produced varied according to the state of concentration 

 of the liquid.) Chloride of that metal remained, which in diS- 

 ferent specimens indicated a quantity of dry muriatic acid, 

 varying from 0.03 to 0.14 per cent, of the strong sulphuric 

 acid used. 



I have in this manner examined the sulphuric acid from 

 Mr. Mac Mullen's, Mr. Jones's, and my father's factories. The 

 specimen which contained 0.03 per cent, was from Mr. Jones, 

 and that which contained 0.14 was from Mr. Mac Mullen's 

 manufactories. 



Having thus obtained a key to the numerous otherwise in* 

 explicable deductions of that gentleman, it is totally unneces- 

 sary for me to give a detailed explanation of the phenomena 

 which he relates. I shall, therefore, merely take up a few of 

 his most important assertions, with a view of showing their 

 total inaccuracy and insufficiency. 



Mr. Mac Mullen sets out by observing, that in his very ex- 

 tensive factory he has had many opportunities of observing 

 the peculiar smell which manganese emits when acted on by 

 sulphuric acid, and that the odour depends on the disengaging 

 of chlorine. 



He then states that he thought it could not be present in the 

 manganese, as a muriate of iron, copper, or lead, metals which 

 that mineral sometimes contains ; because, that before he 

 added the sulphuric acid, he had washed the ore, and the 

 washings had not precipitated nitrate of silver ; and that the 

 water would have removed those muriates if they had been 

 present. 



As Mr. Mac Mullen complains that Mr. Phillips misinter- 

 preted him, I shall take his own words. Mr. Mac Mullen 

 ])roceeds — *' Having in this manner thoroughly satisfied my- 

 self of the existence of chlorine in the black oxide of manga- 

 nese, I was naturally led to inquire in what chemical state 



X 2 



