UNKNOWN

[*NOTE: this translation does not correspond directly to the French version in the 1891 edition [pp.311-313]. The French edition gives a series of different proportions of caseine glue to zinc white ground in water: the first layer: 70 grammes caseine to 5 grammes zinc white the second layer: 60 grammes caseine to 20 grammes zinc white the third layer: 50 grammes caseine to 30 grammes zinc white -A last coating, to be added for greater whiteness: is 40 grammes caseine, and 40 grammes of zinc white. Hence the instructions above, in English, translated directly "Second coat, No.2" are referring to the second layer described in the French text, and in the absence of any mention of these layers according to proportions of materials, does not make any sense in the English version. On the title page of this translation it says that it is translated from the "8th" edition, whereas the British Library edition of 1891 is the 4th edition.]