26 Mr. de Luc on 
40. As in thofe trials the contradi&ion between the marches 
of the flips and the threads was very evident, I was the more 
difappointed to find, that the uncertainty of the real degrees 
of moiflure increafed at that very period : for infiance, fetting 
out from fome dry point, and moiflure increafing, the march of 
a thread of whalebone was evidently in a decreaflng progreffion, 
comparatively to that of a flip of the fame fubftance ; and when 
at laft there was a fuperfluous quantity of water in the veffel, 
and the temperature was made to change, the thread was 
almoft flationary , while the flip had confiderable motions, 
often contrary to the fmall motions of the other ; while it was 
at that very period, that the real degrees of moiflure in the 
veffel could not have been afcertained but by an already fettled 
hygrometer. I had no doubt that thofe anomalies were to be 
attributed to the thread of whalebone , not only becaufe of the 
excels of the fame modification*in other threads ; but alfo con- 
fidering the analogy between the comparative marches of the 
two kinds of hygrofcopes , and thofe of the thermometers , of 
water and quickfllver : but as this was a very important ob- 
ject for natural philofophy, I would not decide it from thofe 
ffrft appearances ; and that confideration led me to a very great 
number of various forts of experiments, which I made in view 
of multiplying at leaf! the indirect fadts with which my theory 
might be compared. However, as at laft I found a more diredt 
means of verification, I fhall only mention that laft clafs of 
experiments. 
