74 Proceedings of Philosophical Societies, [3a-n, 



likewise a large receiver. Mr. Leslie's ingenious method of ex- 

 posing the vapour raised to a surface of sulphuric acid diminished 

 the size requisite^ and saved, a great deal of labour. Dr. 

 Wollaston's apparatus is still more simple. It consists of a glass 

 tube of some length, having tw® balls of an inch in diameter, one 

 at each extremity. One of the bails is to be nearly half full of 

 water, the other empty ; and both balls and tube must be as 

 completely as possible exhausted of air. The tube is to be bent 

 into a right angle at a little distance from each tube. If the 

 empty ball be plunged into a mixture ' of salt and snow, the 

 water in the other ball very easily freezes, though at a distance^ 

 in consequence of the rapid condensation of the vapours l)y 

 the cold. This little instrument Dr. Wollaston calls a chryno- 

 phorus. 



A catalogue of the position of some of the stars near the pole, 

 ascertained by means of the new circular instrument at Green^ 

 wich, by the Astronomer Royal, Mr. Fond, was presented to the 

 Society. By this instrument, he states, the position of stars may 

 he determined with a degree of accuracy before unknown in 

 astronomy. 



A paper by Sir Everard Home, Bart, was likewise read, on the 

 organs of digestion of several birds. These organs were particu- 

 larly described ; but we need not attempt an account of it, as it 

 would not be intelligible without figures. The paper concluded 

 with a comparison between the organs of digestion of birds of 

 the same kind, showing how admirably they are adapted to the 

 situation in which the animal is placed. The cassuary of Java, 

 one of the most fertile islands in the world, where food is 

 abundant, has small digestive glands, a small gizzard, and an 

 enormous length of entrails. In the cassuary of New Holland, 

 tvhere the food is more scanty, the glands and gizzard are larger, 

 and the entrails shorter. In an animal of the same kind in the 

 deserts of Africa, where food is still more scarce, the glands and 

 gizzard are still larger, and the entrails shorter. 



A paper was also read by Mr. Brande, confirming, by farther 

 experiments, the conclusions which he had formerly drawn, re- 

 specting the quantity of alcohol in wines of diiferent kinds. It 

 had been objected to his former conclusions, that the alcohol 

 which he had obtained might have been formed during the pro- 

 cess of distilling the wine, by which means he obtained it. In 

 this paper he describes the method which he fell upon to separate 

 alcohol from wine without the application of any heat. When 

 subacetate of lead is dropt into port wine, a copious precipitate 

 falls, consisting of the whole colouring matter, and the tartaric 

 acid of the wine, in combination with the oxide of lead. When 

 the liquid is now filtered it is colourless, and if it be mixed with 

 a sufiieieot quantity of dry subrauriate of potash, the alcohol 



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