On the Occurrence of Gallium in Clay-ironstone. 399 



On February 10th we received from Mr. C. R. Ridsdale, the 

 Chemist, at the North Eastern Co.'s Steel Works, at Middlesbrough, 

 samples of the following materials : 



1. " Mixer metal," i.e., mixed blast-furnace metal. 



2. Roasted Cleveland iron ore. 



3. Flue dust. 



4. Tap cinder. 



5. Manganese ore. 



6. Lime. 



On February 12th, photographs of the oxy hydrogen flame spectra 

 of these substances were obtained. 



The following are the particulars of this examination : 



1. The roasted Cleveland ore contained iron, sodium, potassium, 



manganese, chromium, nickel, copper, gallium, lead, and 

 calcium. 



2. The blast-furnace metal contained iron, sodium, potassium, 



manganese, nickel, copper, gallium, and lead. 



3. Flue dust contained iron, sodium, potassium, manganese, 



chromium, nickel, copper, silver, gallium (doubtful), lead 

 (strong), calcium, and rubidium. Rubidium was identified 

 by the lines 4202 and 4216. (Thalen.) Calcium by line 4226, 

 in the blue. 



It is evident now that gallium is contained in the ore and is con- 

 centrated in the metal. 



1. The manganese ore (a 15 per cent. Spanish ore) contained 



iron, sodium, potassium, manganese, copper, silver, lead, 

 indium, and calcium. The lines by which the indium and the 

 silver were identified are as follows : 



Indium 4510'2 4101-3 



Silver 3383-5 3282-1 



The occurrence of indium is remarkable, as hitherto it has been 

 found only in zinc blendes. 



2. Tap cinder contained iron, sodium, potassium, manganese, 



copper, and lead. 



3. Lime contained calcium, magnesium, potassium, and sodium, 



a trace of iron, and a trace of manganese. 



The lime showed the following bands, characteristic of lime* : - 

 Band in the orange from 6253 to 6116, degraded towards the 

 more refrangible side. 



Band from 6075 to about 5900. 



* ' Phil. Trans.,' vol. 185, p. 182. 



