38 Experiments on the Yolk of Wool, 



nounced, has an efficacious action on the portion of grease 

 which is not in the saponaceous state ; for I observed that 

 by pouring over wool no more water than the quantity ne-. 

 cessary to cover it completely, it was much better scoured, 

 especially with a slight degree of heat, than when washed in, 

 running water. But I observed also that wool which had 

 remained a long time in its own yolk swelled up, split, and 

 lost its strength ; effects which take place also in too strong 

 soapy water. 



If the water of yolk causes wool to swell and to split in 

 this manner, may it not be possible that this accident often 

 takes place on the backs of the animals, especially during 

 warm damp weather, or when they are shut up in folds the 

 litter of which is not often enough removed ? It may not 

 be impossible also that the acridity of yolk may occasion an 

 irritation in their skin, and prove the cause of some of those 

 maladies to which this organ is subject in these animals, 

 and which must occur chiefly during damp warm weather : 

 fortunately, at this season, they are occasionally exposed to 

 rains, which wash them arid carry off at least a part of this 

 matter, In this respect I am inclined to adopt the opinion 

 of those who think that the washing of sheep during dry 

 warm weather may be useful to their health and to the qua- 

 lity of the wool. 



The loss which wool experiences by scouring is variable. 

 The greatest I ever observed was 45 per cent., and the least 

 35. The wool, indeed, which I washed was exceedingly 

 dry. This loss does not arise entirely from the yolk it con- 

 tains : moisture, earth, and filth of every kind contribute to 

 it also. 



I have made some attempts to bleach scoured wool ; but 

 I confess that I did not carry them so far as they deserved : 

 I observed in general that wool which had been immersed 

 in soapy water bleached much better, by every method, than 

 that which had not been subjected to the same operation. 

 The sulphurous acid dissolved in water bleaches it pretty 

 well ; but it does not remove the yellow colour acquired by 

 wool in the groin and under ihe shoulders of sheep. Wool 

 in liquid sulphurous acid acquires the property of" making 

 a noise between the fingers like sulphurated silk, and at the 

 same time contracts a foetid odour exceedingly strong, 

 which is not dissipated till a long time after. 



I have not tried $ie steam of burnt sulphur ; but every 

 body knows that it whitens wool exceedingly well, and that 

 it is employed by all manufacturers of woollen stuffs to give 

 them the last degree of whiteness. Of all the means I tried 

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