PHYSIOLOGY. 



tion of rattlesnake venom, Dr. Henry Sewall, of 

 the University of Michigan, assumed an analogy 

 between the venom of the poisonous serpent and 

 the ptomaines produced under the influence of 

 bacterial organisms. Both are the outcome of 

 the activity of living protoplasm, although 

 chemically widely distinct, the ptomaines be- 

 longing to the group of alkaloids, while the 

 active principles of the venom, according to 

 Mitchell and Reichert and to Wolfenden, are of 

 proteid nature. If immunity from the fatal ef- 

 fects of snake bite can be secured in an animal 

 by means of repeated inoculation with doses of 

 the poison too small to produce ill effects, we 

 may suspect that the same sort of resistance 

 against germ disease might follow the inocula- 

 tion of the appropriate ptomaine, provided that 

 it is through the products of their metabolism 

 that bacteria produce their fatal effects. In the 

 author's experiments repeated inoculation of 

 pigeons with sub-lethal doses of rattlesnake 

 venom produced a continually increasing resist- 

 ance toward the injurious effects of the poison 

 without apparent influence on the general health 

 of the animal. 



The physiological action of ptomaines from 

 putrefying meat has been studied by M. Gautier, 

 who extracted the alkaloids and examined them 

 according to their solubility in ether, chloroform, 

 and amylic alcohol. The alkaloids obtained by 

 digesting with ether caused in dogs convulsive 

 movements, rapid action of the heart, injection 

 of the ears, stupefaction, and contraction of the 

 pupils. The chloroform extractives accelerated 

 the respiration and the action of the heart and 

 injected the concha. The amylic alcohol alka- 

 loids paralyzed the movements of frogs, dilated 

 the pupil, and killed, with general relaxation of 

 the muscles. Free ptomaines are more danger- 

 ous than their salts, and especially those that 

 are soluble in ether. Alkaloids called leuco- 

 maines are supposed to be formed within the 

 tissues during the process of life. We resist 

 them by elimination and by destruction with 

 oxygen. Elimination is effected by the kidneys, 

 alimentary tract, and skin ; oxidation is proba- 

 bly chiefly effected in the circulating blood. 

 Any cause that diminishes the access of air to 

 the blood, or causes a decrease in the amount 

 of haemoglobin in the body, or the introduction 

 into the blood of substances that prevent the 

 respiratory changes, leads to the accumulation of 

 azotized substances of the nature of ptomaines 

 and leucomaines. 



Ansep, investigating some cases of poisoning 

 by stale sturgeon, at Kharkov, Russia, discovered 

 an alkaloid differing from the ptomaines of 

 Brieges. It is an amorphous, highly alkaline 

 body, forming soluble salts, and extremely toxic. 

 Caustic agents and boiling destroy the toxic 

 power of the alkaloid. The chief characters of 

 the substance are fixity in the solid state or in 

 ethereal solution and slowness of reducing action 

 on the blood. The hypodermic injection of a quar- 

 ter of a milligramme in a dog causes vomiting, 

 mydriasis, general prostration, and slowness of 

 the movements of the heart. The march of the 

 symptoms in the poisoned individual is in har- 

 mony with the results of physiological research, 

 and is held to indicate that the poison first 

 paralyzes the spinal cord, then the medulla 



PORTRAITS, CRAYON. 



729 



oblongata, and acts probably also upon plain 

 muscular tissue. 



. Among the results of recent experiments on 

 the physiological action of various substances 

 are : Uranium nitrate is an irritant poison, pro- 

 ducing gastro-intestinal irritation of more or 

 less intensity. Introduced into the stomach, it 

 checks digestion? and even stops it, but appears 

 to increase somewhat proteid metabolism and 

 the elimination of carbonic acid, and to HUM- 

 the body temperature. On the kidneys it pro- 

 duces effects similar to those found in poison- 

 ing by arsenic, mercury, and phosphorus; and 

 the production of glycosuria is a characteristic 

 symptom. Antipyrin has a decided inhibitory 

 influence on the* proteid metabolism of the 

 healthy human organism, and tends to diminish 

 the volume of the urinary secretion. These con- 

 clusions are, however, contrary to the results re- 

 cently published by Kumagawa. Antifebrin was 

 not regarded as having a pronounced influence 

 on proteid metabolism. It appeared to exercise 

 an inhibitory influence on the excretion of uric 

 acid. Urethran showed a diuretic action, dimin- 

 ished the excretion of nitrogen and sulphur, but 

 increased that of phosphorus. Paraldehyde in- 

 creased somewhat the protolytic action of pep- 

 sin hydrochloric acid, and had an inhibitory in- 

 fluence on the amylolytic ferment of saliva. 'The 

 salts of cobalt and nickel act slowly and only 

 when comparatively large amounts are admin- 

 istered, causing death by stopping the action of 

 the heart, producing disturbance in the ali- 

 mentary tract, inflammation of the mucous mem- 

 brane and intestine, and causing diarrhoea. Both 

 salts tend to produce a partial paralysis of the 

 intestines,.more pronounced possibly with cobalt 

 than with nickel. 



PORTRAITS, CRAYON. To many who 

 know nothing about the art of crayon portrait- 

 ure it seems not only very difficult, but almost 

 unattainable. This impression may be true to 

 a certain extent in the making of free-hand 

 crayons from life, but the advances in the art of 

 photography has made it possible for any person, 

 with a little practice and study, to make a fair 

 crayon portrait over a photographic enlarge- 

 ment. Three kinds of photographic enlarge- 

 ments are used as a basis, and with a little ex- 

 perience the reader can determine for himself 

 which kind will prove the most satisfactory. 



Free-hand crayons are made on the Steinbach 

 crayon paper without any photograph as a basis. 

 Silver enlargements are made on paper coated 

 with a solution of chloride of silver, which the 

 action of light reduces to the salts of silver. 

 This is the oldest form of photography, and 

 has been used since its introduction by Scheele 

 in 1778. Silver enlargements are made by the 

 aid of the sun (and are then called solar enlarge- 

 ments), or can be made with the electric light. 

 Platinum enlargement is a recent advance in 

 photographic printing with iron salts. The 

 process has been worked out by W. Willis, Jr., 

 and is patented. Its principle is that a solution 

 of ferrous oxalate in neutral potassium oxalate 

 is effective as a developer. The platinotype 

 process is the development of printing with the 

 salts of iron. A paper is coated with a solution 

 of ferric oxalate and a platinum salt and then 

 exposed behind a negative. It is then floated 



