The Action of Metals^ &c., on India-rubber. 273 



Description of 

 Cloth. 



Per Cent. 



Oily and \ ^ ., ^ 

 greasy ^uO. 



matters. 



I. White and Black Star Check. 



2. Dark Brown Ring Check 



6. 

 7. 



8. 



9. 



10. 



II. 



12. 

 13- 



14. 

 '5- 



16. 



J7- 

 18. 



19- 



Light 

 Dark 



Check 

 Broken Check 



Gold Check 



Blue Pin Head Check ... 



Ruby Hair Line 



Drab Fine Sheeting 



Black and White Small Check 



Sheeting 



Black and White Large Check 



Sheeting 



Slate Sheeting 



Blue Check Sheeting ... 



Crimson Sheeting 



Black Fine Twill 



Black Broad 



Black Sheeting 



j> >» 



Black Plain Muslin 



0-499 

 0-128 



0-516 



0-548 

 0-648 



0-301 

 0-264 



0-206 



o*445 

 o-i8i 

 0-388 



0-471 

 1-500 



1-252 



1-552 

 2805 

 2-360 



absent 

 present, 

 but cop- 

 per not 

 estimated 

 ditto 

 trace 



present 



absent 

 present 



absent 



trace 



nottested 

 0-332 



present 



0-150 



present 



0-0157 



Appearance of rubber er 

 rubber composition after 

 being heated in the incu- 

 bator at 1^0" F. for 2J 

 days, in each of the five 

 series. 



Good condition 



Bad, and quite des- 

 troyed 



Ditto 



Damaged, but not quite 

 hard 



Hard and quite des- 

 troyed 



Good 



Hard and quite des- 

 troyed 



Good 



Damaged, but not quite 



hard 

 Good 

 Very much damaged, 



rubber quite hard 



Slightly damaged 



The following pieces of cloth were analysed by one of 

 us, because the rubber proofing had perished within a few 

 weeks or months after being applied to them. Besides 

 being analysed, a piece of each was taken, and one-third of 

 it cut off and put aside. The oily and greasy matters 

 were then removed from the other two-thirds by washing 

 with ether : the part so washed was next divided into two 

 equal parts, one put aside and the other boiled with 1% 

 hydrochloric acid solution and washed till all the copper 

 was removed and dried. These three pieces were then 

 joined together, end to end, in a line, and attached to 

 another black cloth similarly divided into three parts, one 



