922 



SCIENCE. 



[X. S. Vol. XXI. No. 546. 



A few of these appear to be undescribed, but 

 most of them are of species that are widely 

 distributed in the West Indian region. 



Dr. Eusby showed specimens of spurious 

 ipecac roots which have found their way into 

 the markets. The true ipecac (from Ceph- 

 aelis Ipecacuanha of the family Eubiaceae) 

 is now hard to obtain and high-priced. Some 

 of the spurious root comes from other species 

 of the same genus, but the most common 

 adulterant is from the genus lonidium (Cal- 

 ceolaria) of the family Violacese. Dr. Eusby 

 exhibited also specimens of Porteranthus 

 stipulatus, which is sometimes called the 

 North American ipecac. 



Dr. Britton showed living plants of two 

 species of Crassulaceas which had come into 

 flower in the greenhouses of the New York 

 Botanical Garden. One was Sedum Nevii, 

 hitherto described from dried material, a spe- 

 cies collected originally in southwestern Vir- 

 ginia, but since found to extend to Indiana. 

 The other was a P achy phy turn from Mexico. 

 Dr. Britton stated that in North America, 

 north of the Isthmus, 284 species of Crassula- 

 ceae may be recognized, distributed in 25 

 genera. Kepresentatives of all these genera 

 have now been studied in the living state. 



Marshall A. Howe, 

 Secretary pro tern. 



DISCUSSION AND CORRESPONDENCE. 



THE METRIC ERROR. 



To THE Editor of Science : In your issue of 

 March 24, Mr. Henry B. Hedrick, of the 

 United States Naval Observatory, Washing- 

 ton, D. C, shifts from one metric fallacy to 

 another. The regulation school children fal- 

 lacy, as illustrated by the Hon. James H. 

 Southard, chainnan of the Committee on 

 Coinage, Weights and Measures, in his report 

 to the House of Kepresentatives in 1902, and 

 by Lord Belhaven in discussing a compulsory 

 metric bill in the House of Lords on February 

 28, 1904, is that the adoption of the metric 

 system will shorten the school life of every 

 child, including all branches of study, from 

 two thirds to three years; in other words, that 

 the eight years will be cut down to seven and 



one third or even to five years. It is on this 

 basis that Mr. Southard estimates a saving of 

 $1,000,000,000 in every generation. It is 

 clearly impossible to save by the adoption of 

 the decimal system any of the time occupied 

 by the study of non-mathematical branches, 

 such as physical training, penmanship, lan- 

 guages, geography, history, nature study, 

 drawing, cooking, sewing or music. The sav- 

 ing must be made in the time devoted to the 

 study of compound numbers, weights and 

 measures, which occupy 20 per cent, of the 

 school arithmetic. Applying this rate, 20 per 

 cent., to the 34J weelis occupied during the 

 eight years by all branches of mathematics, 

 we find 6.8 weeks to be so consumed. This 

 estimate is not only fair, but extremely liberal 

 to the metric system. It is based on the eight- 

 year schedule adopted for the i^ublic schools 

 of New York City. The weekly time of 1,500 

 minutes is apportioned among the different 

 branches, and the uncertain amount of time 

 devoted to study outside of school hours is not 

 included. Thus there is no confusion of 

 schedule weeks with regular weeks. The case 

 is simple. This metric fallacy is the claim 

 that from two thirds to three years of the en- 

 tire school life can be saved by the adoption 

 of the metric system of weights and measures ; 

 when in fact, less than seven weeks is now 

 devoted to compound numbers, weights and 

 measures. 



Turning from this old fallacy, let us con- 

 sider the new one formulated by Mr. Hedrick 

 to the effect that the adoption of the metric 

 system would save ten per cent, of the time 

 devoted to mathematics, or about two thirds of 

 what may be called a mathematical year of 

 school life. In other words, that ' the pupil 

 woiiid be about a year ahead in mathematics 

 at the end of the eight years if he had only the 

 decimal system to learn.' 



In exposing this new fallacy it is unneces- 

 sary to dwell on the fact that the study of 

 weights and measures in the school is merely 

 very superficial memorizing and that the real 

 knowledge of weights and measures is ac- 

 quired outside of the school by using them; 

 nor on the fact that the 34J weeks covers 



