Formalin.

Otago Witness, Issue 2785, 31 July 1907, Page 76

Formalin.

, iPprmatin^ojc^itormyd^de^/has-Jpnsr been 'in, use as; a preservative, and deodoriser. _OrMiially* dfstifled. from tEe> 'red ant '(Formica" 'rufa), ft is"irow prepared! <rom'%po'd"*PFritJ;'etc;.j and^e^en Irom the* oommobV"nel*i& "It is^yeijr deadly in its* action;on:Lfufligi, but it is noh-toxic to that higher or warm-blooded animate. 'Its pro-* pexsiea~ar©. well known 1 ito (certain manufacturers of- perishable foods and othen articles, not so, much, perhaps, in this country as in Germany. ' Purveyors of meat? are- aware of its .usefulness in preventing^ putrefaction, as" it not only prevents tfoa~ development of bacteria, but is ac powerful a germicide as corrosive sublimate. It, is also used by medical men" on account ofj its antiseptic and disinfectant action. At* it vaporises readily, it is employed in the* disinfecting of rooms- and clothing. Formalin was in use at least 15 years ago as a preservative for meat, poultry, game, and fish. These when dipped, in a weak solution remained fresh for a considerable time. It is said that 'even stinking meat is rendered odourless by dipping- it for a minute or, so in formalin solution. Mr Massee-'s use of formalin to prevent decay in ripe fruit is no new discovery, for years ago a Berlin chemist recommended tb»t "fruit sbould -bo dipped in a weak solution of formalin for about a minute, or wiped* with a doth moistened with the solution, to prevent external decomposition." The fact of its vaporising easily reduces the possibility ofi danger from the- use of formalin in th:« manner to a minimum, and with' the additional precaution recommended by' '^Mt^ Massee of immersing the fruit in pure water after it has been dipped in the forWj malm solution there can be no danger whatever. It is even, used! in small quantities^ .to prevent the souring and clotting of milk without in the slightest degree" affecting iter flavour or v food properties. For rinsing; miik cans, pans, and other utensils of the* dairy it is known to be a most effectiver cleanser. It is also used in the same way; by brewers to cleanse beer casks and bottles*' Although formalin is thus shownr to be a most useful article, it must not be employed ' carelessly. Like many otheK articles of the same nature—such as carbolic acid, creosote, sulphate of copper, anil even such drugs arsenic, strychnine, andt belladonna—formalin in its concentrated! state is capable of harm. For most purposes a solution containing on© tablespoon* ' fur 1 of formalin to on© quart of water suf-> fices, and in many cases a much more dilute solution than this is effective; for* instance, Mr Masse© recommends for fruitt a 3 per cent, solution of commercial forma-_ lin (equal 40 per,, cent, of formaldehyde).The fruit h« treated was afterwards eatea by himself and his family, and he ridicule* the suggestion that any possible injury could follow the'consumption of any kind of fruifc that had been treated as he advises. Formalin has long been used to preserve specimens of fruit in bottles for museum and laboratory purposes, in the proportion ofi a tablespoonful of formalin to a quart of water. It not only preserves the form and tissu© for an indefinite time but m man* cases the colour as well, so that fruit thafr has been in formalin for years is absolutely fresh in appearance. Some years age* experiments made to test th© merits of various preservatives for museum purposes-, such as solutions of chloral hydrate, acetic* acid, salt, eulphur of alcohol, glycerine,; formalin, and methylated spirit, gave results greatly in favour of formalin- Ifc must be borne in mind *hat» owing to its vaporising easily, formalin should be kepis tightly corked, and: when used'for museum: purposes hermetically sealed. Even them th© solution should be changed every tew years, or strengthened by the addition of a small quantity of formaldehyde.