Church. — On the Gliemistry of Pliormium tenax. 267 



repi'esent the final percentages of oil absorbed and retained by tlie several 

 samples of P7iormm??i fibre, two experiments being made in each case, and 

 numerous weishinss : — 



Absorption of Mineral Oil (Paraffl7i Oil) by Fibres. 



A, Native — 

 Good. 



B. Machine- 

 Good. 



12-11 



19-41 



13-30 



20-66 



C. Machiiie — 

 Ordinary. 



-D , f n . • A^ 12-11 19-41 22-25 



Percentage of oil retained ^ ^^.g^ 20-66 24-97 



A. Native — 



B. Machine — 



C. Machine — 



Good. 



Good. 



Ordinary. 



10-79 



9-52 



8-91 



11-63 



10-34 



9-64 



Mean 12-70 20-03 23-61 



In order to see how far these numbers really represented the percentages 

 of oil retained by the several samples, it was necessary to ascertain whether 

 the absorption of oil had been accompanied by any loss of hygroscopic 

 moisture. The samples used in this series were therefore re weighed and dried 

 till constant in weight in vacuo over oil of vitriol. The loss of water they 

 then suffered sufficiently proved that the absorption of the oil had driven out 

 but little, if any, of the natural moisture of the fibres. 



Percentage of water lost by 

 oiled fibres in vacuo. 



Mean ... ... 11-21 9-93 9-30 



It thus appears that the fine native dressed fibre absorbs least oil and 



retains during such absorption the highest percentage of hygroscopic moisture. 

 In order further to test the accuracy of the determinations of oil retained 



by the fibres, direct determinations by means of the " ether process" were 



made. The prepared and oiled samples which had been dried in vacuo 



contained the following amounts of oil in 100 parts ; — 



A. Native — B. Machine— C. Machine — 



Good. Good. Ordinary. 



Percentage of oil retained") t n aa -ir, -, a oa oo 



I, v-u ^i u 4. 1 11"00 17-14 20-88 



by the fibre, but removed > -,-, ka to m oa t/^ 



i'' ,1 ' ( 11-54 18-91 20-26 

 by ether ... ... ) 



Mean 11-27 18-03 20-57 



These numbers accord as closely as could be expected with those given in 

 the first table, and show that the fine native dressed fibre retains the least oil 

 amongst the samples ti-ied. 



Oiling Experiments, Series IT. 

 The oil used was the same as that of Series I., but the fibres were dried at 

 100° centigrade (212° Fahrenheit) previous to their being soaked in the oil. 

 It was thought that the removal of the hygroscopic moisture froui the fibres 

 would increase the quantity of oil absorbed, and render its penetration into 

 the fibres more thorougli. This anticipation was not realized, for less oil was 

 absorbed under the single altered condition (of previous drying) of these 



