A, R. Leeds— Dissociation of certain Compounds. 197 
pletely altered. The most important deductions from these 
experiments are— 
1. In the changes induced in living matter by inorganic 
compounds, the character of the change depends more on the 
physical properties of the reagent than on its more purely 
chemical properties. 
_ 2. That the character of the changes is determined by the 
isomorphous relations of the electro-positive element of the 
reagent.* 
3. That among the compounds of the more purely metallic 
elements, the quantity of substances in the same isomorphous 
group required to produce analogous changes in living matter, 
1s less as the atomic weight of the electro-positive element in- 
creases. 
4. That the action of inorganic compounds on living matter 
appears not to be connected with the changes they produce in 
the proximate elements of the solids and fluids, when no longer 
forming part of a living body, at least in so far as our present 
means of research enable us to judge. : 
_ 5. That in living matter we possess a reagent capable of aid- 
ing Us in our investigations on the molecular properties of sub- 
stances. 
San Francisco, California, Dec. Ist, 1873. 
Art. Pe a5 nee the Dissociation of certain Compounds at very 
low Temperatures ; by A. R. LeEps, Prof. Chemistry, Stevens 
Institute of Tasha bape 
. If has been shown by Fittig+ that ammonic chloride, when 
1n solution in water, is decomposed by boiling. H. C. Debbitst 
has recently investigated other salts of ammonia, especially the 
nitrate, sulphate, oxalate and acetate, and has found that all of 
*In a memoir read before the Academie des Sciences, Paris, in June, 1839, I 
Proved that on injecting saline solutions directly into the blood, this physio 
action was determined by the electro-positive element of the compound being but 
little influenced by the acid with which it was combined. 
+ Ann. Chem. Pharm., cxxviii,s. 189.’ + Ber. der Deutsch. Chem. Gesell., v, p. 820. 
