VOL. XXII.] PHILOSOPHICAL TRANSACTIONS. 483 



The Way of boiling the Oil of Wood, called by the Portugueze Azeiie de 

 Pao. — Take 20 ounces of the oil of wood, 10 drams of that of the fruit. Give 

 them 5 or 6 boiHngs, till it comes to be a little yellow. Let it cool, and put to 

 it 5 drams of quick-lime powdered. 



To give the first Grounds called Camiscia. — Take swine's blood and quicklime 

 powdered, mix them well; lay this mixture on the wood, and when it is dry, 

 smooth it with a pumice stone. 



To mahe the black Famish. — Take of the varnish prepared in the sun 6o 

 ounces, stone black alum, (supposed to be a sort of copperas,) dissolved in a 

 little water, 3 drams, 70 drams of lamp oil, called by the Portugueze azeite da 

 candea. It is prepared in a wooden vessel as the prepared varnish, observing to 

 put in the lamp oil at twice. 



To make the Famish of the Colour of Pitch. — Take of the oil of wood crude, 

 called de pao, 40 drams ; of the lamp oil called de candea, crude, 40 drams ; it 

 is prepared in the sun in a wooden vessel as the prepared varnish. 



To make red Varnish. — Take 10 drams of cinnabar, 20 drams of varnish pre- 

 pared, a little oil de candea or lamp oil ; mix them well. 



To make yelloiu Famish. — Take of the yellow colour 10 drams, 30 drams of 

 prepared varnish, with some lamp oil. 



To make Famish of a Musk Colour. — Take of the red varnish 10 drams, of 

 the black varnish 4 drams, mix them well. 



Part of a Letter from the Rev. Mr. Derham to Dr. Sloane, giving an Account 

 of his Observations of the Weather for the Year 1 699. N*^ 262, p. 527. 



Contains the usual columns of barometer, thermometer, rain, wind, &c. 



Mr. Derham adds, I observed last year, that the highest pitch I ever found 

 the mercury at, was 30.40 inches. But Dec. 22 last, the weather being misling 

 and wind northerly, it rose to 30.50 inches, the highest I ever saw it at Upniinster. 



Concerning tke exact Quantity of acid Salts contained in acid Spirits. By 

 M. Homberg.* Communicated by M. Geoffrey, F. R. S. N° 262, p. 530. 



M. Homberg, chemist to the Royal Academy, in a discourse before them, 

 observed, that though we have a very sure way of measuring the quantity of 

 solids, by balances and ordinary weights, yet we cannot come to the same pre- 



* M. Homberg was a zealous cultivator of chemistry. His father was a Saxon, but the son was 

 born at Batavia, in Java. He was early brought to Europe, studied in Germany, and after much 

 travelling in various countries, settled in Paris. He furnished many communications to the French 

 Academy of Sciences, and died in 17 !5, aged 6"3. He was the discoverer of the boracic acid, (whick 

 he called sedative salt,) of the phosphorus which goes by his name, &c. &c. 



3 a2 



