RECIPES. 323 



GOLD SIZE. 



Linseed oil 25 oz. 



Red-lead I oz. 



Powdered white-lead 



Yellow ochre 



Boil the oil and red-lead together for about three hours, taking care it does 

 not burn or boil over ; pour off the clear fluid, and boil again with a mixture 

 of equal parts of the white-lead and yellow ochre, added in small successive 

 portions. Pour off the clear fluid for use. 



BLACK GOLD SIZE. 



Triturate in a mortar I fluid oz. of gold size with sufficient lampblack to 

 form a dense black colour. If too thick, it may be thinned with a little 

 turpentine. 



FINISHING VARNISHES 

 (For white and coloured rings). 



These are made by triturating the various colours with the vehicle in a 

 mortar. It will be found best, after preparing each colour, to place them in 

 saucers such as are used by artists ; the benzol then evaporates, and the colour 

 can be taken up in a brush, as required, by simply moistening it with benzol. 



The vehicle : 



Gum dammar 3 oz. 



Gum mastic I oz,_ 



Benzol 6 oz. 



The colours : 



White oxide of zinc. 



Blue ultramarine. 



Red carmine. 



Black lampblack. 



Green verdigris. 



Yellow chrome-yellow. 



The foregoing formulae are given in order that micro- 

 scopists may, when desirable, be able to compound them 

 for themselves. The author is of the opinion, however, 

 that it will be found cheaper, where only small quantities 

 are required, to purchase from a dealer in microscopical 

 sundries, as most of these articles can only be satisfactorily 

 made in large quantities. On the other hand, he would 



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