and Laboratory Methods. 1249 



HNaCOg, draw off the supernatant solution, which is easily done since the crys- 

 tals of calcium carbonate adhere closely to the glass slide, wash the residue, and 

 then add dilute sulphuric acid. If the precipitate is due to calcium, character- 

 istic crystals of CaSO^. ^H.^O appear. 



In the presence of a great excess of the reagent a double carbonate of cal- 

 cium and sodium separates, having the formula CaCOg. NaoCOg. 5H2O, which 

 crystallizes in stout monoclinic prisms somewhat resembling the short, thin prisms 

 of calcium sulphate. Strontium and barium prevent the formation of the double 

 salt. 



Exercises for Practice. 



(See suggestions given under Zinc.) E. M. Chamot. 



Chemical Laboratory, Cornell University. 



Course in Biology in the Horace Mann High School.* 



Although the" question of the arrangement of courses in natural sciences in 

 their relation to other courses in the high school curriculum, is as yet open to 

 various opinions from different educators, it is, however, quite generally accepted 

 that the courses of botany and zoology should come early in any plan. In the 

 Horace Mann High School, the courses in botany and zoology are given in the 

 first year, and are followed by the courses in physics and chemistry. It is 

 believed that the work in natural history appeals more strongly to pupils in 

 their earlier years of the high school, than to those who pursue the same work 

 later. An objection to the reverse arrangement lies in the fact that the applica- 

 tion of the principles of physics and chemistry to botany and zoology must be 

 repeated in the biological laboratory. 



The course in zoology occupies the first half-year, followed by the botany in the 

 second half-year. This arrangement seems most satisfactory, both because of the 

 greater interest manifest by pupils of that age in the study of animals than plants, 

 and because the materials for botanical work are more available in spring than 

 in fall. Four forty-five minute periods each week are devoted to the work. 



The courses as outlined are complementary to each other; for instance, the 

 "cell" is studied in the zoological part of the work and is not repeated formally 

 in the botany course. 



Throughout the course in biology it is the aim to develop the scientific method 

 of thought and at the same time impart to the student as much as possible of 

 the subject matter of biology, and the economic importance of animals and plants. 

 To this end, attention is given to the form and structure of living organisms and 

 to their development, relationships, physiology and ecology. 



The method of presentation of the subjects of zoology and botany is a depart- 

 ure from the so-called logical method — -that of beginning with simple forms and 

 proceeding to the complex — for the reason that this is not believed to be the best 

 method to pursue with young students. 



* Lloyd, F. E., and Bigelow, M. A. Teachers College Record, Vol. 2, No. i. 



