far, "however, tlie diverse forms still clearly distinguishing the Freiick 

 colonists of the Quebec and Montreal districts of Lower Canada, 

 rather indicate the permaaencj of the cranial race-forms, and their 

 4;onsequent value as a clue even to minute sub-divisions of the same 

 maiion, thaugfe severed for centuries fromi the parent stock. 



THALLIUM. 



The discovery of voltme electricity hj Oalvani, and the applicatiom 

 iof this new power to the decomposition of chenaical bodies by Sir 

 Humphrey Davy, led to the recognition of a large number of elemen- 

 ?tary substances, the existence of which had been until then .unsus- 

 pected- The preparation of the metallic bases of the alkalies, the 

 alkaline earths, and the earths proper, is due either directly or indi- 

 rectly to the application of galvanism, and. no other force, no other 

 method <of analysis Itas been so productive of interesting discoveries 

 as regards the ultimate constitution of matter. M.eceutly5 however, 

 another branch of science, that of spectrum analysis, has bidden fair 

 tto be equally prolific in results, for although its birth dates but from 

 ;a few years back {neglecting Talbot's experiments as not having led 

 to any practical results) n© less than three new metals. Caesium, 

 "Rubidium, and Thallium have already tlirough its means been added 

 to the list of the known elements. 



The first two must often have been under the shemisti's hands, but 

 from similarity^ especially in the platinochlorides, to potassium, have 

 .<;onstantly escaped observation ; indeed the rare mineral Pollux, found 

 an Elba, and supposed to be and described as a silicate of alumina and 

 |)otassa has recently been proved by Pisani to be essentially a silicate 

 >of alumina and oeesium. 



Coesium and Rubidium exist only in exceedingly minute traces in 

 the waters and minerals from which they are extracted, and although 

 from their constant occurrences in certain vegetables, especially the 

 beet-root, they cannot but be considered as essential to the growth of 

 Ihose plants, yet at present their investigation is by no means con:- 

 |)lete^ and no useful applications have as yet been discovered for the 



