THE ALUMNI JOURNAL. 



273 



A simple derivative of formaldehyde is 

 the hexa-methylene-teltamine, obtained 

 from formaldehyde and ammonia — 6CH2 

 0+4NH3:=(CH2)6N,+6H20, knov^^n com- 

 mercially as urotropin and formin, being 

 used as diuretics and uric acid solvents. 

 Formalin has been successfull)^ applied 

 in the removal of the odor of iodoform; in 

 this case, a compound of it and the latter 

 was obtained which is almost devoid of 

 odor. This body, known under the 

 name of "iodoformin, "should not be con- 

 founded with one of similar title obtained 

 by the action of iodo potassium-iodide on 

 hexa-methylene-teltamine, the former 

 being colorless, while the latter is of a 

 reddish color. Again by the action of 

 hydrochloric acid on an aqueous solution 

 of formaldehyde an udditious product, 



chlor-methyl-alcohol (CH.,(^p-|- \ is ob- 

 tained. If two molecules of formalde- 

 hyde unite with one of hydrochloric acid, 



oxy-chlor-methyl ether (0<^ oh OH^ ^^ 



obtained. Both of these compounds read- 

 ily exchange their chlorine atoms for a 

 hydrogen of various amido groups or hy- 

 droxyls thus leading to synthetic prepa- 

 rations. 



An important characteristic possessed 

 by formaldehyde is its action on the gel- 

 atines (being similar to that of a tannin) 

 forming elastic, translucent masses, in- 

 soluble in water, these form excellent 

 emulsion films for photographic purposes 

 which can be kept in any climate. These 

 films can be readily hardened and are 

 called gelatoid paper. 



Formaldehyde appears in trade chiefly 

 in 40 per cent, solution, under the titles 

 of either Formal or Formalin. Lamps 

 are sold which contain methyl alcohol 

 and when ignited give off formaldehyde. 

 A less important role is played by solid 

 formaldehyde which results from poly- 

 merization of the gas being known scien- 



tifically as "tri-oxy-methylene," techni- 

 cally as "paraform" and "triformol." It 

 must be borne in mind that formaldehyde 

 exists in three modifications, the gaseous 

 (CHoO) which is stable in diluted cold 

 aqueous solution, by means of a very low 

 temperature it has been condensed to a 

 liquid. On heating gaseous formalde- 

 hyde it is converted into para-formalde- 

 hyde, which, in more concentrated con- 

 dition, separates as a white floceulent 

 mass. On evaporating a solution of for- 

 maldehyde, a residue of trioxymethylene 

 remains behind; this constitutes a white 

 insoluble mass, which, on contact with 

 water, is decomposed into formaldehyde. 



Commercially, formaldehyde is most 

 largely employed as an antiseptic, anti- 

 ferment and preservative agent. In va- 

 porized condition or aqueous solution it is 

 destructive to bacterial life of all kinds. 

 As sterilizing agent for culture fluids it 

 excelis corrosive sublimate. Where a 

 rapid acting disinfectant is desired, such 

 as chlorine, sulphurous acid or phenol, 

 formalin does not answer so well, as its 

 action is somewhat slower than the above; 

 however, it is peculiarly adapted for dis- 

 infecting bedding, clothing and such fab- 

 rics that are liable to be injured by such 

 agents as chlorine, sulphurous acid, 

 superheated steam, etc. In such cases 

 the disinfection is best carried out by 

 means of the formaldehyde lamp, 320 gm. 

 of methyl alcohol will yield sufl&cient a 

 Idehyde vapor to destroy all forms of 

 bacteria in a room of 28 cubic metres 

 capacity in 24 hours. A specially con- 

 structed formaldehyde lamp is that of 

 Barthel, which is so arranged that the 

 vapors of the aldehyde are mixed with 

 air as rapidly as they are generated, 

 which is necessary, for otherwise polmer- 

 ization takes place, yielding inert pro- 

 ducts. 



Another method of application for for- 

 maldehyde is the formaldehyde-gelatine 



