Defeription of a new Thermometer. === 6 
gard to dyeing wool and filk, in which it may be employed 
with fuccefs ; and in giving an account of this difference, I 
think the'caufe of it may be found in the nature of the gall- 
nuts. 1. The acid which they exclufively contain, as Ber- 
thollet has proved, facilitates the decompofition of the foap 
with which the cottons have been impregnated, and the oil 
then remains fixed in their tiffue, and in a greater quantity,’ . 
as well as in a more intimate combination. 2. The gall- 
nuts, which owe their development to animal bodies, retain 
a character of animalifation, which they tranfmit to the 
vegetable ftuff, and by thefe means augment its affinities 
with the colouring principle of the madder; for it is well 
known of what utility animal fubftances are to facilitate 
this combination. This animalifation becomes ufelefs in 
operating upon woollen or filk. 
X. Defcription of a Thermometer which marks the greateft 
Degrees of Heat and Cold, from one Time of Obfervation 
to another, and may aljo regifier its own Height at every 
Inflant. By Axex. Kerru, Efg. F.R.S. and F_A.S. 
Edin. From the Tranfaétions of the Royal Society of 
Edinburgh, Vol. IV. 1798. 
"TL wermomerers have hitherto been defective for 
meteorological purpofes, in fo far as they only point out the 
degree of heat at the moment of infpeéting them, but do 
not fhew what the difference has been, from the time of one 
obfervation to another. 
The ingenious Robert Hook, in the end of the laf cen- 
tury, mentions his intention of making a thermometer for 
the above purpofe ; but it does not appear that it was ever _ 
executed: neither does he explain how it was to have been 
done. . 
The thermometer, invented by Mr. James Six, as deferibed 
in the 72d volume of the Philofophical Tranfactions of the 
Royal 
