t i 



paper. Tl 'uule- for living the im.ige> obi 



The transferring pictmcs iVoin one MM? .-i" sensitive paper to 

 another. The employment of boiling solutions of hyposulphites, to 

 give increased \\hitor.ess to ealotype and other photoc'raplnc pii - 

 tnre*; and the process of waxing, when the picture h.is born 

 rendered more transparent by these means. |-|u- prvi ot 

 warming thr paper, tlnrinj: the torniation ol" the iinajjr, by pl.ieiiii: 

 A warm plate of iron behind it to inerease the sensibility. Tin 

 employment of iodiml jxipev eveiie.l or rnuleted sensitive by a 

 liquid, containing only a small portion of nitrate of silver, ami 

 SUbsequentK dried; >o a^ to \ live state. The 



\.uvin-i the lights and shadows of a picture by iodide of potassium. 

 and the tixing the picture SO changed The placing n sheet >t" 

 white or v-olouretl paper hehiiul pluMographic piclurc> after having 

 waved them. The obtaining enlarged portraits and pictures h> 

 throwing a magnified image thereof, by lenses, on photographic 

 paper. The application of photography to printing, by arranging 

 suitable letters or figures, so as io form pages, and making photo- 

 graphic images thereof. The system or combination of the tol 

 lowing several photographic processes into one, whereb\ permanent 

 and perfect copies of the positive kind me obtained, namely, 

 the formation of the negative COpy the fixing it, so that it shall 

 have the requisite transparency, and endure great subsequent 

 exposure to the light the formation of the positive from the 

 negative cop> . and its permanent fixation. 



Posirn r 1'uTUMtS. 



Many attempts have been made to produce positive calotype 

 pictures by a Single process, but the methods proposed are all 

 difficult of execution, and r.ucK successful. The following plan wa 

 introduced by Professor drove, at the last meeting of the British 

 Association held at York. Ordinary calotjpe paper is darkened 

 until it assumes * deep brown colour, almost amounting to black; 

 it is then re-dipped into the ordinary solution of iodide of' potas- 

 sium ami dried. M hen required for nse.it is drawn over dilute 

 v id, one part ACid to two-and-a-half parts water. In this 

 state, those parts exposed to the light are rapidh bleached, while 

 the parts not exposed remain unchanged. It is fixed in the usual 

 method. Mr. Grove brought forward, on the same occasion. 

 another process, by Which, a negative oalot>pc ".Js converted into 

 a positive one. An ordinary calotype picture is to be taken in the 



