Composition of Dilute Sulphuric Acid. 



309 



curves prove that errors do exist of larger amounts than these, 

 especially where the two points used in calculating ds/dp were 

 found from different solutions. I 'think, therefore, that I shall 

 be expressing his views if I say that he regards the normal 

 limit of error in the present set of experiments as < 16 x 10 -6 

 and > 8 x 10~ 6 , when the interval between the points used in 

 finding ds/dp is 2 per cent. The estimated maximum error 

 calculated on this basis is shown in the following Table : — 



Table IV. 





-^xio 6 . 













dp 





Deduced 

 from 







Maximum error 

 estimn.fp.rl 



p. 



Observed. 



Calculated 

 from 



Pickering's 

 numbers. 



/3-«. 



y—et. 



num( 



;rically 



greater 

 than 





a. 



formula. 



/3. 



11130 



7- 



+ 13 





less than 



80-54 



11117 



11083 



-34 



30 



15 



80-04 



11251 



11243 



11220 



- 8 



-31 



15 



8 



79-48 



11400 



11354 



11349 



-46 



-51 



32 



16 



79-12 



11412 



11416 



11419 



- 4 



+ 7 



19 



10 



78-62 

 77-11 



11426 

 11673 



11490 

 11660 



11503 



4-64 



77 



43 

 14 



22 



7 



-13 





74-98 



11753 



11766 





+ 13 





16 



8 



73-01 

 71-06 



11767 

 11708 



11769 

 11708 



11703 



+ 2 



'" 



16 

 15 



8 



8 







— 5 



69-10 



11595 



11604 



11592 



+ 9 



- 3 



16 



67-12 



11467 



11469 



11463 



+ 2 



- 4 



16 



8 



65-51 



11311 



11346 



11343 



+35 



+33 



26 



13 



65-12 



11320 



11315 



11313 



— 5 



- 7 



16 



8 



64-50 



11335 



11263 



11262 



-72 



-73 



41 



20 



63-08 



11127 



11143 



11137 



+16 



+ 10 



15 



8 



6101 



10936 



10948 



10934 



+ 12 



— 2 



15 



8 



58-94 

 57-94 



10731 



10602 



10727 

 10615 



10698 

 10596 



- 4 



-33* 



15 



8. 



+ 13 



- 6 



7 4 



56-89 



10466 



10496 



10488 



+30 



+22 



16 8 



54-89 



10275 



10268 



10273 



- 7 



— 2 



16 8 



52-91 

 50-91 



10054 

 9811t 



10047 



9822 



10055 



— 7 



+ 1 



16 8 

 16 8 



+ 11 



48-91 



9599 



9599 



9602 







+ "3 



16 8 



46-94 



9382 



9381 



9390 



- 1 



+ 8 



16 8 



d 2 s 

 * This error may be due to the uncertainty as to the value of -r^ at 

 this point. ' 



t This is given in Mr. Pickering's Table I. as 982. 



In studying this Table one fact must be borne in mind. 

 The last figure in all the columns is doubtful. In order to 



