72 ANNUAL OF SCIENTIFIC DISCOVERY. 



paper mould) produces the peculiar effect seen on the edges of uncut 

 paper. Being caused when the paper is in the state of pulp, it can- 

 not be successfully imitated after the paper is made. 6. The strength 

 of the paper, which is made, not from the worn fibre of old garments, 

 but from new linen and cotton. In its "water-leaf" or unsized con- 

 dition a bank-note will support thirty-six pounds, and when one grain 

 of size has been diffused through it, it will lift half a hundred-weight. 

 The printing processes arc briefly as follows. The bulk of the 

 note is printed from a steel plate, the identity of which is secured by 

 the process of transferring. The paper is moistened for printing, by 

 water driven through its pores, under the pressure of the atmosphere 

 admitted into the exhausted receiver of an air-pump, and 30,000 double 

 notes are thus moistened at the bank in an hour. The ink used in plate- 

 printing is made at the bank, from linseed oil and the charred husks 

 and vines of Rhenish grapes. This so-called Frankfort black affords 

 a characteristic velvety black, very distinguishable in the left-hand 

 corner of the note. The D cam perfects every impression when once 

 drawn through the press. The numbering and cipher printing are 

 also executed in one of the presses in the use of the bank. Several 

 of the processes have been omitted, as not intelligible without draw- 

 ings. 



PRINTERS' INK. 



AN application for the composition of a printing ink has been ad- 

 mitted to be the proper subject, of letters patent, but they could not be 

 issued till after the close of the year ; still, as the invention is regard- 

 ed as an important one, some account of it is deemed proper in this 

 place. Linseed oil and lampblack are the well-known ingredients of 

 printers' ink, and the preparation is necessarily attended with a tedi- 

 ous, disagreeable, and dangerous process of boiling and burning, in 

 order to give the ink the peculiar tenacity required. The invention 

 here set forth consists in the introduction of a new oil, not before used 

 for such purposes, and thus modifying the process, so as to obtain an 

 ink of superior quality, without the dangerous process of burning. 

 Considering the large amount of this material used at the present day, 

 and the comparative cost of the two oils (the expense of the linseed 

 being four times that of the rosin oil), this invention assumes an im- 

 portance in the improvements of the day not usually met with. It is 

 also stated that the introduction of this oil enables the printer to print 

 with delicate and fancy colors, which cannot be done with ink manufac- 

 tured from linseed oil. The oil here referred to, and called rosin oil, 

 is obtained by the destructive distillation of common rosin. Patent 

 Office Report, 1849. 



NEW METHOD OF GILDING PORCELAIN. 



M. GRENON has submitted to the Society for the Encouragement 

 of National Industry, at Paris, an improvement in gilding porcelain, 

 which adds much to its durability. The operation of gilding, as gen- 



