138 BACTEKIAL POISONS. 



EscHERiCH. The gastric juice is the physiological guard 

 against infection by way of the intestines.' 



It is also possible that some of the secretions poured into 

 the intestines have germicidal properties, or that the cells, 

 in absorbing the poisonous proteids, may to a limited ex- 

 tent so alter them that they are no longer poisonous, or 

 that in a perfectly normal condition the liver may be able 

 to prevent these poisons from entering the general circula- 

 tion without change. These are all possibilities, which 

 science at some time in the future will investigate. 



(4) Any germ which is capable of growing and produc- 

 ing an absorbable poison in the intestine is a pathogenic 

 germ. 



It is not necessary that a germ be capable of growing 

 and causing disease and death when injected under the skin 

 or into the blood in order to estarolish its right to rank with 

 the pathogenic germs. In the blood the organism is acted 

 upon by a wholly different fluid from that with which it 

 is surrounded in the intestine, and the germicidal properties 

 of the blood have been unquestionably demonstrated. 



(5) The proper classification of germs in regard to their 

 relation to disease cannot be made from their morphology 

 alone, but must depend largely upon the products of their 

 growth. 



As has been stated, three microorganisms, differing suf- 

 ficiently to be recognized as of different species, produce 

 poisons, all of which induce vomiting and purging, and, 

 when used in sufiicient quantity, death. Morphologically 

 these bacilli may not be closely related, but physiologically 

 they are near akin. 



If these deductions be true, we will try to avoid the 

 introduction into the alimentary canal, not only of the so- 

 called specific pathogenic germs, but of all toxicogenic 

 microorganisms. 



' It has been said that this statement cannot be true, because there are 

 other acids which are more powerful germicides than hydrochloric a«id, 

 but there is no force in this argument. The question is not whether the 

 stomach is supplied with the very best germicide, but whether it is sup- 

 plied with any at a'l. The human eye may not be a perfect mechanism, 

 but it is man's only organ of vision. 



