January 7, 1921] 



SCIENCE 



23 



Accessory. 



corresponding elevation of continents (Arldt 

 and Enquist). 



4. Intensive volcanic activity with accompanying 



soot clouds (Sarasin). 



5. Slight eccentricity of the earth's orbit (Hil- 



debrandt) . 



6. Passing of the solar system - 



through regions of the universe 

 in which there were no stars 

 (Noelke). 



7. Decreased heat radiation of the 



sun (Philippi). 



8. Lesser inclinations of the ecliptic 



(Eekholm). 



9. Decrease of carbon dioxide con- 



tent in the air (Chamberlain 



and Salisbury). 

 10. Distribution of land and sea according to 



Kerner's view. 

 Pliothermal or warm interglacial periods oc- 

 curred under the following circumstances: 



1. Chiefly as a result of low flat continents, 



2. Through absence of deep basins, 



3. Eising of sea floor and depression of continents, 



4. Volcanic inactivity, 



5. Great eccentricity of the earth's orbit, 



6. Parsing of the solar system through regions of 



the universe abounding in stars, 



7. Great radiation of heat from the sun, 



8. Great inclination of the ecliptic, 



9. Increase of the carbon dioxide content of the 



air. 



It is utterly improbable that the interior of the 

 earth contributed to the climatic changes. Polar 

 dislocations are also out of the question, so long 

 as we can not prove that they followed any par- 

 ticular direction, All attempts, likewise, at ex- 

 plaining change in climate from one cause alone 

 are futile. Although at first sight these theories 

 may appear attractive, they can not stand the test 

 of keener criticism. Moreover, nature is too com- 

 plex to permit its being compressed into a single 

 formula. 



Chester A. Eeeds 



American Museum of Natural History 



SPECIAL ARTICLES 



OBSERVATIONS ON THE ACCUMULATION OF 



CARBON DIOXIDE FROM STRAWBERRIES 



IN REFRIGERATOR CARS 



During the years 1918 and 1919 and in con- 

 nection with shipping tests of strawberries in 



refrigerator ears being made under the direc- 

 tion of Mr. H. J. Eamsay and Mr. V. W. 

 Ridley then of the Bureau of Markets, the 

 Avi-iter was able to make observations on the 

 carbon dioxide and oxygen content of the air 

 in refrigerator cars and the effect of ventila- 

 tion on the accumulation of carbon dioxide. 

 A brief summary of the results follows: 



The percentage of carbon dioxide and 

 of oxygen was determined by means of a 

 commercial Orasatt apparatus — samples being 

 drawn through lead tubing one end of which 

 was placed in the part of the car from which 

 it was desired to take samples and the other 

 run out at one comer of the door. During 

 transit analyses were made at icing stations 

 and at other times when the train stopped 

 long enough. Duplicate analyses were made 

 when time permitted, and in all cases several 

 hundred cubic centimeters were thrown away 

 before the sample was drawn for analysis. 



The results of the analyses made during 

 three of these tests are summarized in Table 

 I. In the tests of 1918 the berries were 

 loaded at a temperature of about 68° to 70° 

 P. and one car was ventilated by raising the 

 hatches at diagonal corners of the cai-. The 

 berries loaded in the test of 1919 were at a 

 temperature of 76°-78° P., one car being ven- 

 tilated by raised hatches, and the other that 

 reported in the last column of Table I., by 

 two six-inch pipes, installed at opposite ends 

 of the car. 



From the table it is apparent that there is 

 no great accumulation of carbon dioxide in 

 the air of the unventilated cars in transit. 

 The maximum amount 2.5 per cent., was 

 reached in a car loaded at Monett, Mo., seven 

 hours after the doors were closed. When the 

 ear was re-iced the carbon dioxide content 

 dropped to 0.7 per cent. From this it in- 

 creased again to 1.3 per cent., but at the next 

 icing it dropped to 0.6 per cent, and never 

 exceeded this amount during the remainder 

 of the trip. 



The accumulation of carbon dioxide in un- 

 ventilated refrigerator cars loaded with straw- 

 berries has been found not to exceed 2.5 per 



