296 AN ADDRESS ON CORROSIVE SUBLIMATE 



proceeds in this sort of way ^ ; he dips a very small piece of silk thread into 

 a fluid containing the spores of the Bacillus anthracis, known to be highly resist- 

 ing to the various agencies inimical to low organisms. After this silk thread 

 has become dry, he dips it in the antiseptic solution to be tested, keeping it 

 there for a minute, half a minute, five minutes, or any length of time that is 

 required. He then, by means of water or alcohol, or some fluid known not to 

 influence the vitality of the spores, washes away the antiseptic from the thread, 

 and brings into play his beautiful method of solid culture-material. He places 

 the little bit of silk thread upon a piece of gelatine properly provided with 

 nutritious material, and of course scrupulously pure, and observes, by means of 

 the microscope, whether the spores in the silk thread develop or not. He 

 ascertained, by experiments of this character, that a solution of only one part 

 of corrosive sublimate in 20,000 parts of water was amply adequate absolutely 

 to destroy the vitality of the spores of the Bacillus anthracis, about the most 

 resisting spores that are known. But he found also that as weak a solution 

 of the sublimate as one to 300,000 parts of a solution of extract of meat was 

 sufficient to prevent the development of the spores so long as they remained 

 in it ; but when the silk thread, having been for any length of time in this 

 exceedingly weak solution, was withdrawn from it, washed, and then placed 

 upon the nutritious gelatine, development occurred as if the spores had not 

 been exposed at all to any injurious agency ; and thus Koch established in 

 a most definite manner the distinction, and a very important one it is, between 

 two different effects of antiseptic agents — one, the action by which the vitality 

 of organisms is destroyed ; and the other, that by which development is simply 

 arrested, or prevented temporarily from occurring, without the vitality of the 

 spores being interfered with. The former we may term ' germicidal action '. 

 For the latter, it is somewhat difficult to find a good English term. I happened, 

 I believe, to be the first to use the word ' inhibitory ' in English physiology, by 

 the advice of my old friend Dr. Sharpey, with reference to an early paper I was 

 about to publish on what the Germans term the ' Hemmungs-Nervensystem ' "^ ; 

 and as this same word Hemmung is used by the Germans for this checking or 

 suspending action of antiseptics, without destruction of vitality, and as it is 

 very important that we should have some term which distinguishes the one 

 action from the other, I may venture to employ this same word ' inhibitory ' — 

 a good old English word — for this action of antiseptics, and to speak of their 

 ' inhibitory action ' as distinguished from their * germicidal action ' . 



Now, these properties of corrosive sublimate were such as no other antiseptic 



^ Vide ' Desinfection ', Von Dr. Robert Koch. Mittheilungen des Kaiserlichen Gesundheits-Atntes, 

 I. Band, 1881. ^ See vol. i, p. 87. 





