222 



MR J. Y. BUCHANAN ON THE 



I have been fortunate enough to have as assistants, attained the same high degree of 

 exactness in his experimental work, so soon as he perceived that, when he took the 

 necessary trouble with the work, it was rewarded by increased accuracy of results. 

 This has been my invariable experience. Comparisons of work done on solutions of the 

 same concentration of the same salt by Mr Royal-Da wson, and afterwards by Mr 

 Bos WORTH, are quoted in the memoir, and they furnish evidence of the excellence of 

 the work put out by both these chemists. 



Nearly the whole of the experimental work of this memoir has been done by the 

 gentlemen just mentioned. It would, however, be unjust if I did not refer to the great 

 and valuable work with the hydrometer done for me at an earlier date by my old and 

 valued friend and former assistant, Mr Andrew King of the Heriot-Watt College, 

 Edinburgh. The exactness of his work is of the highest order, and his intimate know- 

 ledge of, and sympathy with, my work for many years has been of the utmost value to 

 me, and I wish to take this occasion to make public acknowledgment of the debt 

 of gratitude which I owe to him. 



APPENDIX A. 



Densities of the Solutions at T. 



In the following tables the specific gravities of the solutions have been reduced to 

 their value when referred to that of distilled water at 4" C. as unity. The factors 

 used for this purpose are : — 



for T= 15-0° 19-5° 23-0° 26-0° 



factor- 0-999173 0-998372 0-997614 0-996879 



For example, 15.815. of ^ NaCl is 1 '020564. Therefore its density 4.8150 = 0-999173 15.815. = 

 1-019720. 



CHLORIDES. MCI. 



M = 



Na. 



K. 



K. 



Rb. 



Cs. 



K. 



Rb. 



Cs. 



t= 



m. 

 1/2 

 14 

 1/8 

 1/16 

 1/32 

 1/64 

 1/128 

 1/256 

 1/512 



15-0° C. 



19-5° C. 



23-0° C. 



1-019720 

 1-009597 

 1-004427 

 1-001821 

 1-000494 

 0-999827 

 0-999495 



1-022321 

 1-011063 

 1-005080 

 1-002123 

 1-000659 

 0-999888 

 0-999538 



1-021312 

 1-010023 

 1-004251 

 1-001340 

 0-999859 

 0-999112 

 0-998736 

 0-9985G5 

 0-998454 



1-041446 

 1-020204 

 1 009377 

 1-003903 

 1-001139 

 0-999770 

 0-999078 

 0-998721 

 0-998535 



1-060842 

 1-030059 

 1-014340 

 1-006395 

 1-002400 

 1000396 

 0-999395 

 0-998885 

 0-998620 



1-000531 



1 003086 



1-005549 



