1872.] Chemistry. 409 
A very good wood varnish for furniture and other wooden objects is made by 
adding to 1 kilo. of fluid copal varnish 15°62 grms. of best boiled linseed oil, 
and heating the mixture. The wood to be varnished is first coated with 
a solution of gelatine, to which either some precipitated chalk or some red 
ochre is added, according to the nature of the wood. When the coat of var- 
nish is dry the article is rubbed with a solution of wax in ether. 
It is well known that it requires some tact to bend a glass tube with an even 
curb and without collapsing its sides, and many chemists never do succeed in 
bending them skilfully. Prof. J. Lawrence Smith bends them satisfactorily by 
using the flame given by the Bunsen burner described in his article on 
alkali determination in silicates in vol. xxiii. of the ‘Chemical News.” The 
extremity of the burner is flattened out sa as to give a short and thin but 
broad flame, something like the flame of an ordinary gas-burner. The tube is 
placed in this flame and turned round and round, until a good heat is given to 
the tube; it is then withdrawn from the flame and can be bent with a perfe& 
curve and without collapse of the sides of the tube. A tube of 1 centimetre 
and more can be thus bent very readily. 
Sulphur is recommended by M. J. Ménard as a lubricating material. To 100 
kilos. of good colza oil add 5 kilos. of sulphur, and heat this mixture to from 
130° to 140° until all the sulphur is dissolved. It is said that, being a bad con- 
ductor of heat, sulphur prevents the heat caused by the friction of machinery 
being carried over upon the oil, which can therefore serve for a longer period than 
usual as a lubricating medium. 
Glycerine has been found by experience to be useful as a means of 
increasing the elasticity and strength of leather. C. Méne states that hides 
which have been partly tanned by the usual process, may be greatly improved 
—especially if required for machine-belts—by being soaked for some time in 
glycerine. 
CHEMICAL SCIENCE. 
It will be remembered that in 1869 a Lectureship was founded by the 
Chemical Society in honour of the illustrious Faraday, to be held by some 
eminent foreign savant, who during the term of his tenure, was to deliver a 
discourse before the Society. The second ‘“‘ Faraday Lecture” was delivered 
on May 30th by Professor Cannizzaro, of Palermo, at the Lecture Theatre of 
the Royal Institution. The learned Professor’s discourse was entitled ‘* Con- 
sidérations sur quelques Points de l’Enseignement Théorique de la Chemie.” 
On Friday a dinner was given to the Professor, at which about 150 were 
present, including the Italian Ambassador and the Right Hon. the Chancellor 
of the Exchequer. 
At the meeting of the chemical section of the German Association for the 
Advancement of Science, at Rostock, Professor Schulze read a paper on the 
direct oxidation of carbon by means of permanganate of potash in an alkaline 
solution, which excited lively debate, and was justly regarded as one of the 
most important chemical discoveries of the year. In addition to copious 
quantities of oxalic acid and of other produés not yet determined, the author 
obtained an acid to which he has given the name of anthraconic, and which 
he found to closely resemble mellitic acid in its properties. The experiment 
was repeated with charcoal purified in a stream of chlorine gas, also by 
calcining cream of tartar, by the reduction of carbonic acid with phosphorus, 
and from graphite. All of these varieties of carbon yielded analogous results. 
So great was the interest manifested in the announcement, that the leading 
chemists adjourned to the Professor’s laboratory, there to repeat the tests and 
to examine into the nature of the incidental products. They soon came to 
the conclusion that the new body was identical with mellitic acid. By treating 
the anthraconic acid with caustic soda, benzol was produced, which was con- 
verted into nitrobenzol in the usual manner, and from this produé aniline 
was manufactured. 
VOL. I. (N.S.) 3G 
