These are basic substances which either exist preformed in the proteid molecule or are produced by tissue metabolism. The leucomaines are cleavage products while the ptomaines are formed by the splitting of the molecule through the action of bacteria. Their properties are determined more by the character of the parent substance than by that of the bacteria, as in the case of the ptomaines.

The sources of the leucomaines are the nucleins of cell nuclei and the proteids of cytoplasm. The great majority are not toxic, but their antecedents and nucleinic acid, histons and protamins and the amino derivatives purin and pyrimidin, are distinctly so.

They may be divided into five groups: 1. The Purin or uric acid. 2. The pyrimidin. 3. The hexon bases. 4. The creatinin. 5. Leucomaines of doubtful nature.

The Purins

The Purins. The general action of these bodies resembles that of caffein, as they occasion increased irritability of muscle and the nervous system, marked diuresis, permanent muscular contraction with coagulation which resembles that produced by extreme heat or cold, and paralysis.

Hypoxcinthin

Hypoxcinthin, C5H4N40, although it has no effect upon muscle, causes increased nervous irritability and tetanic convulsions. Gaucher and Kolisch found that it produced parenchymatous nephritis when injected into rabbits and guinea pigs for a period of a month or over. Hall (10) injected grain daily for fifty days into rabbits and found that it produced degeneration of the renal convuluted tubules, and the liver cells showed evidences of the action of a cellular toxin. In a rabbit of three and one-half pounds weight, Hamilton produced great mental excitement and irritability, the reflexes being affected by the slightest tap, by the injection of 0.01 g. of hypoxanthin. This state of hyper-sensitiveness soon gave way to somnolence and torpor with insensibility to pain, the pupils being widely dilated and the pupillary reflexes lost.

Adenin

Adenin, C5H5N5, occurs together with guanin and hypoxanthin as a decomposition product of nuclein and may be obtained from all tissues rich in nucleated cells. In tea it exists preformed, the extract containing 6 g. per L. Sweetbreads which are rich in the antecedents of adenin may cause diarrhea, anorexia, nausea and vomiting, headache, malaise and abdominal pain if taken in excess, a chain of symptoms not unlike that of acute indigestion. Minkowski has shown that adenin is a violent poison, and that it causes rapid heart action and speedy death when injected subcutaneously. In small doses it causes intense inflammation of the duodenal mucous membrane which may lead to actual necrosis. In the kidneys true inflammation is occasioned with casts and albumin in the urine and sphereoliths of uric acid in the renal cortex as well as in the urine.

Parcixanthin

Parcixanthin, C7H8N402, sometimes called urotheo-bromin, is present in exceedingly minute quantities (0.0001 per cent.) in normal urine. Ratchford claims that it is excreted in excess during an attack of migrim and immediately following attacks of a certain form of epilepsy, but his views are disputed by Pfaff who was unable to verify his results. The paraxanthin separated from one quart of urine passed after an epileptic attack, when injected into a guinea pig - increased reflex excitability followed by general clonic spasms, followed by tetanus, irregular and gasping respiration, trismus, involuntary urinations. Myosis and nystagmus frequently accompany the convulsions and death occurs, apparently from asphyxia, in from one to ten minutes. Schmiedeberg found that injections produced rigor of the muscles which became of wooden or waxy consistency. Dyspnea was an early symptom, the respirations dropping far below normal, even becoming suspended for a time, the heart's action continuing regular until just before death.

Paraxanthin is derived from caffein by the splitting off of the methyl group, and it is claimed that its toxicity is increased by its association with small quantities of ammonia.