Pommer, however, found that tartaric acid is scarcely less active than oxalic acid when injected into the blood. When fifteen grains dissolved in half an ounce of water were injected into the femoral vein of a dog in four doses, difficult breathing and discharge of fæces and urine were produced after each operation, and death speedily ensued without any other particular symptom. As in the instance of oxalic acid, the blood in the great veins was not apparently changed in any of its physical qualities. The heart continued contractile long after death, while in the case of oxalic acid its contractility was suddenly extinguished.[428] CHAPTER VII. OF THE ALKALIS AND ALKALINE SALTS. The second order of the class of irritants comprehends the alkalis, some of the alkaline salts, and lime. The species which it includes are little allied to one another except in chemical composition; and in particular they are little allied in physiological properties. It appears impossible, however, to make a better arrangement than that proposed by Orfila, which will therefore be here followed. Most of the poisons of the second order are powerful local irritants. Some of them likewise act indirectly on distant organs; and a few are more distinguished by their remote than by their local effects. This order may be conveniently divided into two groups,—the one embracing the two fixed alkalis with their carbonates, nitrates, and chlorides, and also lime,—the other ammonia, with its salts, and likewise the alkaline sulphurets. The action of the first group is purely irritant and strictly local. When concentrated, the fixed alkalis and their carbonates produce chemical decomposition, softening the animal tissues, and reducing them eventually to a pulpy mass; which change depends on their possessing the power, as chemical agents, of dissolving almost all the soft solids of the body. When much diluted, they produce inflammation, without corroding the textures; and it does not appear that they are even then absorbed in such quantity as to prove injurious to any remote organ. The action of the alkaline nitrates and of lime is that of irritants only; at least their chemical action is obscure and feeble. _Of the Fixed Alkalis and their Carbonates._ _Section_ I.—_Of their Tests._