MJX'JIAM'S ANT) USEFUL ARTS. 77 



dry, the '/I placed in rnu filer-:, when the essence, being 



Volatilized, leaves a d'-posit of platina dust firmly united t.o the 

 jrl'i . \V r l)il<; l.vvo or three wi-.i-.L~ are n<-'-<--sary for the manufac- 

 lun- of ordinary mirror-., the new pro'-<--s only requires a few 



hours. 



Jo a hygienic point of view, the now process i- absolutely in- 

 valuable, :md i- :\. true rrij't to humanity. So f;jr from bein;r r- v. 

 po-<-d to the l'-a-.t injurious ern;i n;U ion froj/j ;i poi-onous '-ubsl ance, 

 the most '-.x'jiiisite n'-:tUif:-.s ;ind puj'iiy pi'cvuil in t.lj<: f':if-toi-y. 

 X''if.ij'-r dust, nor rnoi-fur<- m:ty !>': admitted, for <'V<;i - y ^ruin of 

 !u-t. would uUr.'i/;!. f.ljr; Jjfjiiid :md j'-;i.\'- HJ<; <_'-];r-:-. <:xjyo-/:d, wlnlo 

 dampness would coni.rafl. lli'- phttirjifcrous d'-po~it. 



If fli<: /n<-l:ii)i/'-.d glass ''Oinp.'!!-'--: f':ivontlj]y in rlunihility and 

 oh':;i.]Hj'--s wit.Ji Ui<-, ordinary mirror, it f-:i.nrjot fn.il soon to '-upr;r- 

 <s':dc it ont ii-f;)y. Kff;n uft*:) 1 t)j': laps*: of years, it i *> \v<:\\ known 

 that 1h<t f/;(-]-f;ury will ci'umlj]'; away f'ror/i oui 1 iniirors, and that 

 little cracks will upj^ ; ;ir in it. A. gift wljif.-h has \><-.<-\\ for a Jon^ 

 tJuic in on': po-ition, if reversed, will often suff':r injuri'-s, fh<: 



mercury having a tendency to fall downwaj-d. 'J'h': bar-k^round 

 of foil is also so extremely fragile and d';Ji':at.':, that it must. ij<; 



pi-'-'-i-j-'. '-d j'rom a':'-id'-nt by t.h<: double prot:'-iion of a st.out flan- 

 /j<-l and a fr:ini'-. it, is also ^r'-atly ;df':'-t<-d by thf: vai'iat ions of 

 olimat.r:, and it, i -; <:v:n s;i.id that, the d:nn:i^'-s -ustairj^d by rnanu- 

 i'a':t,u)-(:rs who <-:.porf /niri'oi'- to ti'opjcal count )'i^- amount to .00 

 per ':'-nt. of th': valu<- of t h'-ir <:xportat ions. 'J'h': jjlatina, on 

 'ontr.i.! \ , d-fi( s all ;lijnai-- and every atmosphedc change ; 

 ;i - to 'onomy, it is certain thai, the rj':\v method is far Jess 

 hiv; than the old. 



Jt has, beside-, other advantage-. r j'o make a f^ood rniri'or in 

 the ordinary mannei', the glass rnu-1 be ab-oJutely i'ree from fla'/ 

 bufjbles, :i.nd -treak^, and of the mo-t |j'-rfe-et t rarj-jtai'erj'-y ; wliile 

 by the, new oj>eraliotj the most d'-fecfive ^Ia~.s, even t.he eornrnon 

 bottle, rrla'-s, in :-pit<- of its dee-j) tint, be<, v om<--, alter rnanipulalion, 

 an irreproachable mirror. Another condition with the mirrors of 

 the past, has been the paralleJi-m of the, 1 wo sides; a neee:-sity 

 which disappears under the new proce , wljie-h de-mand-. orjly 

 that the surface which receives the platiniferous d'-j^o-it shall be 

 j>rejjared in the customary manne-i\ when a perfect mirror is ob- 

 tained in spite of the inequalities of its surface. Glass thus pre- 

 pared may be also ir-ed for windows, bein^ on the one side 

 reflecting an'l from the other ti -an -parent., admirable for apart- 

 ments whose occupants de-ire Ji^ht atjd a view outside, but do 

 riot wi-h to b': seen by passers-by. The platina ean also be dis- 

 j>o-ed on the ^l;r-s in vai'ious designs: tfje mo-t elegant lace cur- 

 tain may be -tamped indelibly on the panes of a window, while 

 ^race-fid arabe-'jues on f(la-.s will oj-namerit our public buildings. 

 M. S alvetat be.Jie,ves that thi-, invention will make u revolution in 

 the decorative art. 



M.W i -I.- I OK MICA. 



Puscher, of Nui-er/jbej-^-, lately KU^ested the use of mica for 



7* 



