484 PHILOSOPHICAL TRANSACTIONS. [aNNO I'OO, 



cision in liquors ; and still less can we know the precise quantity of the difFerent 

 matters contained in those liquors; as, what is the quantity of acid volatile salt 

 contained in acid spirits : but for that purpose he has contrived a new areometer, 

 or a measure of liquors, which is thus described: 



A, fig. 3, pi. 12, is a glass bottle like a small matrass, of which the neck bc 

 is so small, that a drop of water in it takes up the space of 5 or 6 lines ; near 

 that neck is a small capillary tube D, about 6 lines long, and parallel to the neck 

 BC ; in the opening at b it is a little dilated, in fashion of a tunnel, for pouring 

 more easily the liquors in the bottle ; and the little tube d is for giving a vent 

 to the air contained in the vessel when the liquor is poured in b ; the point c is 

 a little mark at the same height as the end of the little tube d. 



When the vessel is filled with some liquor for the experiments, it is poured 



in by the opening b, until it goes out by the small tube d ; and if the height of 



the liquor is even with the mark c, it is right ; if lower, we must fill more to 



that point ; if higher, we must strike softly on the opening b, till the overplus 



of the liquor be even with the point c in the neck of the bottle. By that means 



we have always exactly the same volume of liquor, and we can know how much 



the same volume of the several liquors weighs precisely, the one more than 



another; but as the volume of liquors is not always the same, and changes 



according to the alteration of the weather, we must consider the variation of 



the weatlier, when making the experiments at several times, and when we will 



compare the weight of the liquor weighed in summer time, with the weight of 



another weighed in winter ; for the same liquor being more rarefied in the hot 



season, the same volume of it will be more weighty in cold weather than in 



warm ; for this purpose M. Homberg has given a table of the various weights of 



the most usual liquors in the coldest and hottest seasons, as follows : 



In Summer. 



5 5 gr- 

 The areometer full of mercury ..11 O 6 , . . . 



Full of oil of tartar 1 3 8 . . . . 



Spirit of urine 1 O 32 ... . 



Oil of vitriol 1 3 58 



Spirit of nitre. I 1 40 ... . 



Spirit of salt 1 O 30 ... . 



Aqua fortis 1 1 38 



Vinegar O 7 55.... 



Spirit of wine 6 47 . . • . 



River Water O 7 53 



• I Distilled water O 7 50 



This empty areometer weighs 1 dram and 28 gr. 



