44 DISINFECTANT 



prove conclusively that carbolic acid has a special action on the fermentation induced 

 by organised matter ; it not only arrests it instantly when in progress, but it prevents 

 the development of future fermentation. 



4 The action of the tar acids was now examined on certain chemical bodies, which 

 are supposed to act by fermentation, in order to see if they were influenced in the same 

 manner. 



4 A solution of diastase (infusion of malt) was mixed with thick starch paste, and a 

 one-por-cent. solution of carbolic acid. On gently heating for a short time, the starch 

 was converted into dextrine, as completely as if no carbolic acid had been present. 



4 Amygdalin was mixed with synaptase (emulsion of sweet almonds) in the presence 

 of carbolic acid. The formation of the essential oil took place with apparently the 

 same readiness as if carbolic acid had been absent. 1 



4 The foregoing results show that carbolic acid has no action on purely chemical 

 ferments. These consist of definite nitrogenous compounds acting simply by chemical 

 affinity, and therefore ought not to be classed with true ferments, which are living 

 bodies. It therefore appears that carbolic acid acts by attacking vitality in some 

 mysterious way, and where an eflect is merely due to so-called catalytic force, it exerts 

 no interfering action. 



4 The action of carbolic acid on vitality was then tested in other ways : 



4 Cheese mites were immersed in water, where they lived for several hours. A few 

 drops of a solution of carbolic acid containing one per cent, added to the liquid, killed 

 them instantly. 



4 An aqueous solution of carbolic acid was added to water in which a small fish was 

 swimming. It proved fatal in a few minutes. 



4 A very minute quantity of a weak solution of carbolic acid was added, under the 

 microscope, to water containing various infusoria, such as bacteria, vibrios, spirilla, 

 amcebaea, monads, euglensea, paramecia, rotifera, and vorticellse. The acid proved 

 instantly fatal, arresting the movements of the animalcules at once. 



4 These animalcules are the almost invariable accompaniments of putrefactive fer- 

 mentation. The above experiment has been tried with putrid blood, sour paste, and 

 decayed cheese, and in every instance the destruction of vitality and the arrest of 

 putrefaction has been simultaneous. 



4 Caterpillars, beetles, crickets, fleas, moths, and gnats were covered with a glass, 

 the inside of which was smeared with carbolic acid. The vapour proved quickly 

 fatal. It allays the pain caused by the stings of bees, wasps, hornets, and gnats, if 

 applied pure, or in strong solution, to the wounded part. 



' I find it recorded by Dr. Lemaire and other observers that carbolic acid vapour 

 will also kill flies, ants and their eggs, lice, bugs, tics, acari, mosquitoes, aphides, 

 butterflies, earwigs, wood-lice, cockchafers, centipedes, and other insects of this size ; 

 its vapour, however, does not appear to be strong enough to act injuriously on animals 

 larger than mice. When such animals are killed with it, their bodies dry up in the 

 air, and resist putrefaction for some time. 



4 From the intense aversion shown by all insects to the odour of carbolic acid, it is 

 probable that the plentiful use of this agent would effectually preserve cattle from 

 those terrible scourges met with in certain parts of Africa, the zimb and tsetse-fly. 

 The effects following the bite of the latter have been described to me as being almost 

 identical with the symptoms of cattle plague. 



4 M. Lucien Biard, in speaking of the invasions of the large ants of Mexico, says 

 that when one of their battalions threatens his house, he sprinkles a little carbolic acid 

 in front of it. The army immodiatety makes a detour to avoid the obstacle. 



4 When an animal is killed by the injection of a saturated aqueous solution of car- 

 bolic acid into its veins, circulation is instantly arrested, the blood is not coagulatnl, 

 and no alteration, either in the shape or the appearance of the globules, is detected 

 under the microscope. The only apparent change consists in the immobility of the 

 globules. 



' In the 4 Annales do Chemie et do Physique ' for October 1865, there is a letter from 

 M. Bechamp to M. Dumas, in which it is said that creosote appears to bo tho 

 agent which most strongly opposes the development of organic ferments, l.ut that it 

 does not interfere with the living ferments or animacules when they are once 

 developed. This assertion is in direct opposition to all my experiments, about 

 the accuracy of which I have no doubt whatever, having submitted them to repeated 

 tests. The powerful action which carbolic acid exerts on tho phenomena of life is tho 

 most remarkable property which it possesses. It may be looked upon as tho teM 

 for distinguishing vital from purely physical phenomena, and in most cases its act inn 

 is characterised by the certainty and definiteness of a chemical re-agent. In the 



1 These last two experiments are confirmatory of a statement In Dr. Lcmairc'a work, ' Sar 1'Adde 

 ph6nlque.' 



