April 3, 1885/ 



SCIENCE 



279 



Assuming, as he does, that these crania are all 

 pre-glacial, and finding among them both long and 

 short skulls, Dr. Kollmann arrives inevitably at the 

 -conclusion that already in pre-glacial times the men 

 •of America had cranial and facial forms widely dif- 

 ferentiated into varieties which have persisted until 

 the present time, in spite of lapse of time, and change 

 of environment. The persistence of type leads him 

 further to question the probability of an alteration 

 of race-characters from change of environment, or 

 the possibility of the development of another, more 

 perfect race. 



A KINDERGARTEN SYSTEM OF 

 CHEMISTRY. 



It appears to be a law, that, whenever a 

 hypothesis of fundamental importance is intro- 

 duced into a science, it is utilized for all sorts 

 of purposes for which it was never intended. 

 This is certainly true of the valence hypothesis 

 in chemistry. The conception that the smallest 

 particles or atoms of the elements differ from 

 each other in regard to the number of other 

 atoms with which the}* can enter into combina- 

 tion, is the result of a profound consideration of 

 the facts of chemistry, and its significance can 

 be comprehended only b}* those who have made 

 a deep stud}* of these facts. The valence hypoth- 

 esis is utterly meaningless to those who do not 

 know considerable about chemical substances 

 and their action upon each other. Notwith- 

 standing this, the mere mechanical considera- 

 tions involved in it are so simple, and can be 

 so readily illustrated, that we find incompetent 

 teachers thrusting them upon the attention of 

 beginners even before any sort of notion has 

 been conveyed in regard to the nature of 

 chemical action, or of the distinction between 

 elementaiy and compound bodies. We need 

 only pick up any one of the small text-books 

 in common use, and, ten chances to one, we 

 shall find an example of the kind of treatment 

 referred to. 



It would be difficult, however, to find any- 

 thing to equal '-The chemists' and students' 

 assistant, or, Kindergarten system of chemis- 

 try," which has recently been brought to our 

 -attention. The author or inventor of this sys- 

 tem evidently thinks that the essential things 

 in chemistry are not compounds, but formulas ; 

 that, if one can manipulate formulas w T ith suffi- 

 cient skill, he knows chemistiy. Now, in or- 

 der to deal with the formulas, it is not at all 

 necessary to know any thing about the com- 

 pounds represented. A very few simple princi- 

 ples, which a child can thoroughly comprehend, 



The cheminttf an'PtffMdenW cws'stant ; or'Kin'lprgnrtPii fti/s- 

 4em of chemistry. By William Farmek. New Vork, Author, 

 JSS4. 



are alone required. We are therefore at last 

 in a position to study chemistiy without any 

 reference to chemical phenomena. The odor 

 of chlorine and of sulphuretted hydrogen, the 

 activity of oxygen, the conduct of acids to- 

 wards bases, need no longer be known to the 

 student of chemistry. Laboratories for in- 

 struction are superfluous. All we need is ' The 

 chemists' assistant.' This wonderful thing 

 consists of a box containing a number of blocks 

 of different shapes. The simplest blocks, which 

 represent the simplest atoms, have but one 

 angle : others have two, three, four, five, or six 

 angles, and represent respectively the bivalent, 

 trivalent, quadrivalent, etc., elements. A col- 

 lection of such blocks Iry itself is not a very 

 harmful thing, and we can conceive of the 

 blocks being used in connection with a course 

 of instruction in chemistry without leading to 

 an entirely false notion concerning the things 

 represented. Their use, however, would require 

 the greatest care, as they would be more likely 

 to do harm than good. When we read the 

 author's explanatory words, we first recognize 

 the enormity of the system with which he has 

 presented us. After stating in general terms 

 how the blocks are to be used, he says, " For 

 lectures or class illustrations, this system will 

 be exceedingly useful ; for the illustrations on 

 the charts and blackboard will address the eye 

 as well as the mind of the student, and conse- 

 quently will lead to a quicker conception of 

 the subject lectured upon. 



u As this system is identical with that of 

 the kindergarten, the young students will be 

 charmed with the various forms which can be 

 made by the elements, some of which are ex- 

 hibited in the following illustrations." 



We then find some illustrations of chemical 

 reactions which certainly do charm the eye of 

 even the old student. The first one represents 

 what takes place when water acts upon calci- 

 um oxide. Ox}'gen, with its two points, joins 

 two single-pointed lrydrogen blocks, and we 

 have water. Calcium (two-pointed) fits close 

 to oxygen (also two-pointed), and we have 

 lime. The change to the hydrate, or, as com- 

 mon people call it, slaked lime, is too abrupt : 

 we therefore have an intermediate stage repre- 

 sented. This is called the ; cracked-up ' stage, 

 though, from the general appearance of the 

 formulas, we are inclined to think that it might 

 better be called the l exploded ' stage. Final- 

 ly order is restored, and we have a peaceful, 

 symmetrical-looking group, which, we are glad 

 to be told, is 4 calcic hydrate.' The idea of 

 including in chemical equations the intermedi- 

 ate ' cracked-up ' stage, is, we believe, original 



