FOOTSORES ON CATTLE: See Veterinary Formulas.
FORMALDEHYDE:
See also Disinfectants, Foods, and Milk.
Commercial Formaldehyde.
The small amount of uncondensed gas is then led through a series of two washers. The “formol” thus obtained is a mixture of water, methyl alcohol, and 30 to 40 per cent of formaldehyde. It is rectified in a still, by which the free methyl alcohol is removed and pure formol obtained, containing 40 per cent of formaldehyde, chiefly in the form of the acetal. Rectification must not be pushed too far, otherwise the formaldehyde may become polymerized into trioxmethylene. When once oxidation starts, the heat generated is sufficient to keep the oxidizers red hot, so that the process works practically automatically.
Determination Of The Presence Of Formaldehyde In Solutions.
FORMALIN FOR GRAIN SMUT: See Grain. {363}
FRAMES: THEIR PROTECTION FROM FLIES.
Since there is great risk of damaging the gilt when trying to remove flyspecks with spirits of wine, it has been found serviceable to cover gilding with a copal varnish. This hardens and will stand rough treatment, and may be renewed wherever removed.
FRAME CLEANING: See Cleaning Preparations and Methods.