[a. F. philtre (1568 in Hatz.-Darm.), ad. L. philtrum, a. Gr. love-charm, love-potion, f. -, stem of to love, dear, loved, loving + -, suffix of instrument.]

1. A potion or drug (rarely, a charm of other kind) supposed to be capable of exciting sexual love, esp. towards a particular person; a love-potion or love-charm. Sometimes loosely, a potion or drug to produce some magical effect, a magic potion. Also fig.


It looks to me as though philtrum (which is not in the OED on line edition) derives from philtre, which is. The philtrum, as Dr. Bill pointed out, is where on the face the philtre was placed for greatest effect.

Filter on the other hand, is described in the OED thusly:

[ME. filtre, a. OF. filtre, ad. med.L. filtrum: see FELT]

1. = FELT n. Also a piece of felt. Obs.

c1400 MANDEVILLE (Roxb.) xxvi. 125 an es he sette apon a blak filtre, with e whilk ai lift him vppe and settez him in his trone. Ibid. xxxiv. 152 ai dwell all in tentez made of blakk filtre.



2. a. A piece of felt, woollen cloth, paper, or other substance, through which liquids are passed to free them from matter held in suspension.
Now only with reference to chemical manipulation, where the filter is usually of unsized paper.

1563 T. GALE Antidot. II. 76b, Distill them by a fylture or thorowe a lyttle bagge, or by a peece of clothe. 1683 PETTUS Fleta Min. I. (1686) 214 Dissolve the Vitriol and purify it through a Filtre. 1769 LANE in Phil. Trans. LIX. 220 The clear liquor being decanted, the remainder was passed through a filter. 1812 SIR H. DAVY Chem. Philos. 285 The whole is then to be poured upon a filtre of cloth. 1846 J. BAXTER Libr. Pract. Agric. (ed. 4) I. 53 Collected on a filter, washed and dried.

Felt:

[OE. felt = MDu. and Du. vilt, OHG. filz (MHG. vilz, mod.G. filz), Sw. and Da. filt:OTeut. *felto-z-, filtiz-:pre-Teut. *peldos-, -es-. Kluge compares OSlav. plst of same meaning.
From the WGer. *filtir:OTeut. *filtiz comes the med.L. filtrum FILTER.]

1. A kind of cloth or stuff made of wool, or of wool and fur or hair, fulled or wrought into a compact substance by rolling and pressure, with lees or size. Also pl.

c1000 ÆLFRIC Gloss. in Wr.-Wülcker 120 Centrum, uel filtrum, felt. c1440 Promp. Parv. 154/2 Feelte or quylte, filtrum. c1450 J. de Garlande in Wright Voc. 124 Capellarii faciunt capella (hattys) de fultro (feltte). 1555 EDEN Decades 281 Clokes made of whyte feltes. 1613 PURCHAS Pilgrimage IV. xiii. (1614) 411 They have also Idolls of Felt. 1675 OGILBY Brit. 66 Their Trade is in making Serges and Felts. 1801 WOLCOTT (P. Pindar) Tears & Smiles Wks. 1812 V. 58 Mute Silence with her feet in felt, Did stalk from vale to vale. 1848 DICKENS Dombey xviii, After dark there come some visitors, with shoes of felt. 1892 Daily News 18 May 2/7 A fair trade is passing in..felts.



2. a. A piece of this material, something made of felt. In early use: A filter made of felt or cloth.

Filter comes from felt and is apparently Teutonic in origin, while philtrum comes from the Greek root phil. I noted the Teutonic peldos, so I looked up pelt, but that seems not to be connected with peldos. Would have brought it in a nice circle had it done so, since felt is made from hair or fur taken from pelts.

But, regardless of the fact that filter and philtre aren't related, I reserve the paranomasiac license to use them as pun cognates.

TEd






TEd