THE favourable manner in which the first edition of this little 

 Work has been received, and the rapidity with which a large 

 impression has been exhausted, have determined the Publishers to 

 reprint it, with such additions and modifications as will render it 

 more generally acceptable. In addition to the instructions for the 

 Calotype and Energiatype, which have been carefully revised, this 

 Manual will contain Directions for conducting all the Photographic 

 processes on paper, which can be of any use to amateurs. The 

 demand for simple and concise treatises on many other branches of 

 science and art, has further induced them to change the general 

 title of the series ; and the present Work will therefore appear as 

 NUMBER ONE, OF WILLATS'S SCIENTIFIC MANUALS. 



LONDON, 1st June, 1845. 



