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H IReeume of tbe Itlae^ of 3formaHn/ 



By George C. Freeborn, M.D. 



THIS reagent is also known in commerce under the names of 

 formol and formalose. It is a forty per cent, solution of 

 the gaseous body, formic aldehyde (HCOH), in water. It 

 is prepared by oxidising methylic alcohol and bringing the result- 

 ing gas into solution in water. It is non-inflammable. It mixes in 

 all proportions with alcohol and water. Its power of penetration 

 is good. Its keeping properties are good. A series of experiments 

 were instituted to determine this point, with the following results : 

 A forty per cent, solution was kept in open and closed vessels, 

 daily tests being made. The results of these experiments showed 

 that the solutions did not decompose. There was a loss of i*6 

 per cent, of formalin, and an increase of o"i per cent, of formic 

 acid. Polymerisation took place with the formation of a butter- 

 like mass containing sixty per cent, of formic aldehyde ; this dried 

 up into a hard mass which contained eighty-five per cent, of formic 

 aldehyde. Fish and others advise that it be kept in darkened 

 bottles, as the light may decompose it. In an experience of two 

 years I have not noted any appreciable change in the solutions. 



Attention was first called to the antiseptic properties of formalin 

 by F. Blum, in 1893. In 1894 Pottevin found that, when formalin 

 was added to cultures of bacteria, their growth was arrested. 

 Cohn also found that solutions and the vapour of formalin killed 

 bacteria both in the vegetative and in the spore stage, but that it 

 had but little action on moulds, unless used in strong solutions. 

 This want of action on moulds has also been noted by many other 

 observers. Miquel, in experimenting with gaseous formic aldehyde, 

 found that it acted as a disinfectant for small and loose objects 

 confined in small spaces, but was not reliable for disinfecting large 

 rooms. Cambier and Brochet also experimented with the gaseous 

 form, with results similar to those of Miquel. Their laboratory 



* Read before the New York Pathological Society, March 23, 1896. From 

 the New York Medical Journal. 



