204 



ANIMAL AMIDES. 



frothy-like substance increases more and more. The solution 

 becomes muddy from a small quantity of white flocks interposed 

 through it, while a gelatinous translucent substance collects on 

 the bottom of the vessel. The frothy substance, according to 

 Mulder, is a compound of four atoms of collin, and one atom 

 of chlorous acid, or 4 (C 13 H 10 Az 2 O 5 ) + Cr O 3 . The white 

 flocks are composed of C 13 H 10 Az 2 O 5 + Cr O 3 . The gela- 

 tinous substance at the bottom is 1^ (C 12 H 10 Az 2 O 5 ) + Cr O 3 . 

 This chloride of collin is insoluble in water and alcohol. It 

 reacts as an acid, and this property cannot be destroyed by wash- 

 ing it in warm water. It has also the smell of chlorine or rather 

 of chlorous acid. If we dissolve this chloride of collin by means 

 of ammonia, and put the solution into a glass tube standing over 

 mercury, azotic gas is slowly disengaged from it, and the whole 

 becomes a frothy mucus. If we evaporate the ammoniacal solu- 

 tion to dryness over the water bath, and mix the dry residue with 

 alcohol to extract a little sal-ammoniac which it contains, and 

 then dry the precipitate, we get a transparent matter of a pale- 

 yellow colour, which softens in water, melts when gently heated, 

 and gelatinizes imperfectly on cooling. It dissolves in a great 

 deal of water, and in its properties rather resembles gum than 

 gelatin, but reactives exhibit the same phenomena as with unal- 

 tered collin. 



Chloride of collin becomes gelatinous in acetic acid, and dis- 

 solves in it. Water renders the solution muddy, but prussiate 

 of potash causes no precipitate, showing that no albumen has 

 been formed. 



If we saturate the solution of chloride of collin with carbonate 

 of potash, and evaporate, we get a mixture of chloride of potas- 

 sium, and a small quantity of yellow matter.* 



So far as is known, neither bromine nor iodine have the pro- 

 perty of combining with collin. 



When collin is digested with concentrated sulphuric acid, 

 Braconnot has shown that it is converted into leucin, sugar of 

 collin, and a substance containing less azote than collin does. 

 Nitric acid, when digested with collin, causes the disengagement 

 of a little azotic acid gas, the collin is dissolved except an oily 

 matter, which swims on the surface, and converted partly into 



* Berzelius, Traite de Chimio, vii. 706. 



