THALLIUM. CROOKES. 123 



So high praise from that quarter we have good reason to 

 deem a positive indication of gross errors hidden by a pre- 

 tentious show of extraordinary precision. We shall find 

 these indications exact in regard to the work of Crookes. 

 The chemists who have adopted this " model " have reason 

 to regret it. Compare Ramsay and Aston, under Boron, in 

 Part III. 



Every material thing, substances, balances, weights, all 

 have been most scrupulously tested and verified, we here are 

 informed through Clarke. 



But how about the experimentor himself, Mr. William 

 Crookes? Has he been tested? 



Yes, the marvelous concordance proves that in the labora- 

 tory he was not " crooked," but went the narrow path that 

 leadeth to the goal of minute probable errors. In other 

 words, Mr. William Crookes did agree very closely with Mr. 

 William Crookes in all laboratory work throughout proba- 

 bly many months. 



But Chemistry is NOT merely a fine manual handicraft of 

 the laboratory ; it is not merely an Art, but is also a Science ; 

 in my humble opinion, it is the science of sciences. 



Have we any assurance that Mr. \Villiam Crookes, the 

 expert manipulator and chemical artisan, was really a chemist 

 or that Sir William Crookes to-day has become a real 

 chemist, in knowledge and understanding as well as in 

 weighing, igniting and dissolving? 



I shall not pronounce judgment now; but examine his 

 work, which alone must testify hereto. 



Testing the Laboratory Work of Mr. Crookes. 



The unit of weight used by Mr. Crookes is the grain. 

 The weighings are recorded to the millionth of the grain 

 which is almost down to the hundred millionth of the 

 gramme. There is accuracy, at least on the face of it, in 

 print; we shall come back to this subject. 



In this first examination we next note the amount of 

 metal used. It ranges, in the ten determinations, from 12 

 to 30 grammes, being from 180 to 500 grains in the first 

 determination. Certainly ample thallium was used, possi- 

 bly too much, in the first determination. We shall examine. 



