36i Further Expetiments and Observations on lud'we. 



It is soluble in excess of chlorionic acid, and in this way may 

 be separated from the hX^'zV jiowder; it aftoids a little moisture 

 during its detonation, but it is not possible to say whether this 

 js formed in the process, or whether it is water adhering to the 

 compound, for the te;nperaturo of its decomijosition is so low, 

 that a proper degree of heat cannot be applied to render it dry. 



When two bodies so similar in their characters and in the 

 compoynds they form, as iodine and chlorine, act upon suIj- 

 "stancesat the same time, it is diftk-ult to form a judgement of 

 the different parts that they play in th.e new chemical arrange- 

 fnents produced. When I found that the chlorionic compound 

 formed a strong acid by solution in water, I at first sus])ected 

 that water was decomposed and hvclroionic acid and eueblorine 

 formed ; there was no effervescence in the process, and the pro- 

 portions agree the supposition ; but I tind that solution of 

 euchlorine instantly decomjicses hvdroionic acid and precipitates 

 iodine, which is afterwards redissolved by the chlorine set free ; 

 and nitric acid, which decomposes hydroionic acid, has no ac- 

 tion on chlorionic acid. 



It was possible likewise that if water was decomposed, mu- 

 riatic acid and a couipound of iodine and oxygen miglit exist in 

 the solution; 1 endeavoured to ascertain if this was the case by 

 distilling the solution at different temperatures and collecting 

 the products, but I obtained always the same fluid. 



When coloured solution of chlorionic acid is boiled with hyper- 

 ox\-inuriate of yjotassa, it loses its colour, and chlorine is given 

 off from it ; but in tlris case it likewise gradually loses its acidity, 

 and a substance wliich yields iodine by heat with much efferve- 

 scence, and wliich is probably oxv])otassame, Is precipitated. 



It appears to me most jirobable that the acid property of the 

 chlcH-ionic compound depends upon the combination of the two 

 bodies; audits action upon solutions of the atkalies-aad the_, 

 earths may be easily explained^ .wlien it is considered that chlo- 

 rine has a greater teiidenicy thaiV'iddiue to form double com*: 

 pounds with, the metals, and that iodine has a greater fendt^Sidi^ . 

 than chlorine to form triple dbmpounds;,iyith oxygen andthd 

 metals. -^ '' ■''"'.">,-y^.. 



When in the case of the action Vf the chloriomi^^iSwftpound 

 on fixed alkaline llsivia the chlorine\s not in great eX't^sf^ 

 iodine is always set frtc, because as \ is easy to ptrc&ye ft'^ 

 tiie proportions in v.-hich^ey combine', there is not Rui^^it 

 oxygen detached from t!ie ^flli; by chlorine to form the frfple 

 compound ; and if the e-^mnatlon of the composition of oxy- 

 potassame giyen in the fii/t section, be accurate, supposing^ffS 

 none of tile double coniKfnuid of iodine is formed, a s^mmi^^ 



■^fnust 



