86 BACTERIAL POISONS OF INFECTIOUS DISEASES. 



Buchner found that the cells of many bacteria contain pyogenetic 

 proteids. The amount of these substances in bacterial cells varies 

 with the kind of germ, and some species (the bacillus prodigiosus, 

 for instance), seem to contain no such bodies. The bacillus pyocy- 

 aneus contains a large quantity of this proteid and is suitable for 

 lecture demonstration. The germs are taken from potato cultures, 

 rubbed up with water, and then treated with about fifty volumes of 

 a 0.5 per cent, solution of caustic potash. This forms in the cold a 

 mucilaginous mass which dissolves at the temperature of the water- 

 bath, and after being heated for several hours the fluid is filtered 

 through a number of small filters ; the first portion should be refil- 

 tered. The filtrate is a greenish fluid (pyocyanin) which by the 

 careful addition of acetic or hydrochloric acid (an excess is to be 

 avoided) forms a voluminous precipitate (pyocyaneus proteid). This 

 precipitate should be collected on a filter, washed with water, then 

 suspended in water, and a few drops of a soda solution added, when 

 a dark brown fluid, with a tendency to gelatinize, in the cold, con- 

 taining about 10 per cent, of the proteid, is obtained. 13.254 grams 

 of the moist bacteria yield 1.44 gram of dry bacterial substance, 

 and this, after the treatment given above, furnishes 0.2739 gram of 

 dry proteid = 19.3 per cent. This proteid leaves 11.62 per cent, of 

 ash, which contains phosphoric acid, but consists principally of sodium 

 chlorid. Much smaller amounts of proteids were obtained from 

 other organisms, but the Eberth germ, bacillus subtilis, lactic acid 

 bacillus, red bacillus from potato, and staphylococcus pyogenes 

 aureus furnish considerable quantities. 



The chemotactic properties of these proteids were tested in the 

 following manner : The dissolved proteid was placed in a spindle- 

 shaped glass tube, and this, after being sterilized, was introduced 

 under the skin of the back of a rabbit with antiseptic precautions, 

 and the ends of the tube broken off subcutaneously. After from 

 two to three days the tubes thus prepared were removed and found 

 to contain, in addition to some of the proteid, several cubic millime- 

 ters of fibrinous pus, which was examined microscopically and by the 

 preparation of cultures, which remained sterile. The proteid of the 

 Eberth bacillus was found to have specially marked pyogenetic prop- 

 erties. More extended investigation demonstrated tiiat certain other 

 proteids also have pyogenetic properties. The subcutaneous injec- 

 tion of sterilized preparations of wheat flour and ground peas caused 

 suppuration. Negative results were obtained with starch and solu- 

 tions of di-sodium hydric phosphate ; from this it is concluded that 

 the active agent in the flour is its gluten. Pepton was employed 

 without effect, while gelatin was found to act energetically. Alka- 

 line albuminates were prepared from muscle, liver, lungs and kidney, 

 by treating finely divided portions of these organs with potash and 

 proceeding as in the preparation of bacterial proteids ; all of these 



