l89 on silk worms. &ct. 3. 



wafhed with quicklime and water, it would tend 

 much to promote cleanlinefs at a small expence, and 

 augment the healthinefs of the worms, as well as that 

 of the persons who attend them. 



The circumstance of the silk worm never sleeping 

 during the night, is a new particular respecting the 

 natural history of this animal, the notice of which we 

 owe to mifs Rhodes, and which I suppose is perfect- 

 ly well founded. From this very circumstance, how- 

 ever, it would seem that nature had intended that 

 light or darknefs ihould make little difference to this 

 singular animal. My fair correspondent has, I 

 fhould suppose, committed a small mistake when ihfr 

 supposes the silk worm is a native of polar regionSj 

 wh^re only, there is no night at one season of the 

 year ; for though some parts of China, which seems 

 on all hands to be allowed to be the native place of 

 Jhe siik worm, approach to the polar circle, yet, as 

 the greatest part of that country extends towards 

 the tropical regions, where the day and night are 

 nearly of an equal length, we may rather believe it 

 was there, where the mulberry thrives best, that the 

 silk worm was first produced. But this is a matter 

 merely speculative ; for we know that nature may 



their \\h, witbout taking away either cheir dead companlona, or their ur- 

 dure or litter. J sprinkled w'.th chalk the wormsof oniy two of these jars, 

 and kept the two others to compare witli them. 



" In those without fime, 1 never obtained neither irOre nor lefs thaa 

 jhree small and imperfect cocoons, (chiqua ou icuffard,) and in the 

 two that were sprinkled with lime, I had very often twelve, and never 

 Jefs th?n nine fine full sized firm cocoons." 



This experiment affords the most satisfactory pro»f of the utility of 

 this procefs. From a number of trials he found, that even when the 

 worms were covered with a -very large proportion of Ijjjie; they oever 

 weie is any way incommoded by it, 



