ACTUAL ERRORS OF THE MEAX. 27 



If we don't know the Tenth, we don't know the Thousandth. 



That is, as a matter of fact, the atomic weight of gold 

 found by the chemical determinations of Mallet ranges 

 about equally on both sides of 197 to the extent of three 

 tenths, making the entire range or uncertainty fully six 

 tenths. Now when the best chemical research made leaves 

 the atomic weight of gold uncertain to the extent of the 

 range of six tenths of the unit employed, we are justified in 

 considering the hundreds and the thousandths displayed in 

 this research as quantities utterly unknown, so far as actual 

 chemical determination is concerned. 



Surely, the second and even more so, the third decimal 

 in all of these determinations of Professor Mallet cannot 

 for a moment be taken as chemical facts determined by 

 chemical laboratory work, but they are evidently not exper- 

 imental scientific data at all. 



They are extra-polations made by carrying arithmetical 

 calculations beyond the reach of the degree of accuracy of 

 the experimental work done. 



Mallet Suffers from Morbus Stasii. 



Furthermore, this diagram, representing to scale the 

 actual values given by Professor Mallet himself in the Amer- 

 ican Chemical Journal, shows plainly that the atomic weight 

 found varied considerably with the amount of gold actually 

 used in the particular chemical determination. 



In Series IV, VII and III, the individual dots form ap- 

 proximately a line rising as the amount of gold increases; 

 in Series VI the rise is seen to be perpendicular. In Series 

 I the values tend downward as the amount of gold in-creases. 



But it is the first condition of value of any series of chem- 

 ical analysis of any one given substance, that the final 

 result must be independent of the amount of material used 

 in the analysis. 



That is, the per cent found must be the same, whether 2 

 or 4 or more grammes of the material analyzed has been 

 employed. Of course, no two analysis will give the same 



