183 
ON A NEW METHOD OF WRITING ON PLATES OF ZINC 
FOR LABELLING PLANTS. 
M. Henry Braconnot, the celebrated French chemist, of Nancy, to whom we 
are indebted for the curious transformation of rags and other similar vegetable sub- 
stances into starch, gum, and sugar, by the agency of oil of vitriol, and whose name 
is well known in the chemical world for various researches connected with the 
analysis of vegetable substances, has given, in the last number of the Annates de 
Chimie et de Physique, a preparation for writing on plates of zinc to label plants. 
The writer having a dislike to painting in oil, which is often inconvenient, and 
never endures a long time, resolved to turn his attention to some other way which 
would prove both ready and durable. The system of writing on zinc with a black 
crayon, which was accidentally discovered by M. Symon, an amateur at Brussels, 
and noticed in the Revue Horticole for October, 1832, and the Bon Jardinier for 
1833, possessing many imperfections, led M. Braconnot to try some exneriments, 
being anxious to obtain a liquid, or a species of ink which would be perfectly durable 
when exposed to the changeableness of the weather, and also one with which he 
could write with ease. This end, after several proofs, he is induced to believe he 
has in a great measure attained. 
If it answers, he will have done both the botanists and amateurs a real service. 
The preparation is as follows : — 
Take verdigris in pow’der, one part ; sal-ammoniac in powder, one part ; lamp 
black (noir de fum£e), half a part ; water, ten parts. 
Mix these in a glass or pot mortar, at first only adding as much water as will 
mix them well, then add the remainder of the water ; when placed in a vessel, let it 
be well shaken up from time to time, and in a few days it will be ready for use. This 
is not only excellent for labelling plants, but also for marking objects it is wished 
to preserve in low, wet situations, and for marking keys, becoming quickly dry, and 
being very durable.— A nn. de Chim. et de Phys. 
