(Eckholm).

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 occurred under the following circumstances:

1. Chiefly as a result of low flat continents, 2. Through absence of deep basins,

3. Rising of sea floor and depression of continents, 4. Volcanic inactivity,

5. Great eccentricity of the earth's orbit,

6. Passing 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 particular direction. All attempts, likewise, at explaining 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 complex to permit its being compressed into a single formula.

CHESTER A. REEDS 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 connection with shipping tests of strawberries in

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 corner 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° F. and one car was ventilated by raising the hatches at diagonal corners of the car. The berries loaded in the test of 1919 were at a temperature of 76°-78° F., one car being ventilated 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 car was re-iced the carbon dioxide content dropped to 0.7 per cent. From this it increased 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 unventilated refrigerator cars loaded with strawberries has been found not to exceed 2.5 per

24

BURBAU OF PLANT INDUSTRY, WASHINGTON, D. C.

(Continued)

the Forest Products Laboratory indicate th
cattle food can be prepared from eastern
pine sawdust and that it has considerable
value. The cattle food was prepared by dige
the sawdust for 15 to 20 minutes with 1.8
cent. sulphuric acid at a steam pressure of a
After cooking
120 pounds per square inch.
sugars were extracted with water and the
removed from the solution by means of lime.
liquor containing the sugar was evaporated
thick syrup and mixed with the digested re
which had been previously dried. The whole
then dried to a moisture content of 15 per
It is shown that when the product has a gr
moisture content than 15 per cent. the ke
qualities are not good. Leaching experiment
moved all but 2.04 per cent. of the total acid
all but 7.16 per cent. of the total sugar. A
parative analysis of the wood before and
conversion shows that cold water soluble,
water soluble and NaOH soluble substance
greatly increased but the ether soluble subst
are almost unchanged by the treatment. The
toses are reduced 46.4 per cent, while the m
pentosans are not affected. The total cellul
The sugars pro
reduced by 21.68 per cent.
correspond to 71.5 per cent. of the cellulos
moved by the digestion. The lignin conte
unchanged. The erude fiber corresponds to
75 per cent of that in the original wood.
cellulose is greatly altered by the treatment.
tically the whole of the cellulose obtained i
uble in 17.5 per cent, alkali. It is reprecipi
from the alkaline solution by dilution with
After fiering no precipitation of beta-cel
is obtained upon acidification with strong
seid.

A comparison of wood cellulose and cotton
Jose: S. A. MAHOOD and D. E. CABLE. Samy
wood cellulose and cotton cellulose which had
subjected to various conditions of cooking
bleaching were analyzed by determining a n
of constants on them, including ash, mei
alkali solubility, pentosan and methyl per
content, methoxy content, ether extract, cell
lignin and copper number": for the purpos
of following the changes which take place in
cellulose on successive cooking and ble
treatment with a view to increasing the yiel
purified cellulose by varying these condition
(2) to determine so far as possible the peiz
similarity or difference of cellulose from woo

that from cotton. The data show that wood cellulose most nearly corresponding to cotton, taking munition linters as a standard, is obtained by recooking "easy bleaching" sulphite pulp with soda and bleaching with two per cent. of bleaching powder. The practise of checking wood cellulose according to the specifications for cotton is a questionable procedure.

Supply and preparation of wood for the manufacture of pulp: HUGH P. BAKER.

Parchmentizing paper and the reaction of mordants: J. E. MINOR. The work of Schwalbe and Becker recently published confirms theories of the author as to the reactions which occur on the decomposition of cellulose during beating. The hydrolysis of cellulose forms dextrines which are mucilaginous, soluble in water and easily reduce Fehling solution. These dextrines are readily adsorbed by pure cellulose thus constituting the reactive, insoluble, colloidal hydrocellulose, and in this position they catalyze further cellulose hydrolysis. Complete hydrolysis leaves only soluble dextrines or sugars. For a mucilaginous accumulation as is desired for making parchment paper, the velocity of the initial reaction must be catalyzed, either by the hemi-celluloses of wood incrustation, or by acid treatment of pulp prior to beating. Acid treatment of pulp reduces the time required to beat to mucilage to one half or one tenth the original amount required, and increases the strength of the paper made from it. Pulp mucilage has a greater power of splitting salts and adsorbing metal ions than has cellulose and, therefore, assists in holding size, dye, coating, etc. Metal impregnation weakens paper strength.

Is it feasible to form a section of cellulose chemistry? G. J. ESSELEN, JR.

Solvents for phosgene: CHARLES BASKERVILLE. An impelling factor in causing the Germans to sign the Armistice was a knowledge of the rapid development of the stupendous poison gas program of the United States. One of the earliest gases, a real gas, used by the Germans, was phosgene. It had been manufactured on a small scale in Germany before the war. Small amounts were exported to the United States prior to 1914. It was being produced in this country for similar uses after the blockade had shut off the importation of chemicals in the manufacture of which the Germans had made a specialty. It was transported in small quantities liquefied in cylinders. When hostilities ceased we were producing the

poison gas for war purposes at the rate of fifty tons a day, with a program nearly completed for a much larger production. Soon after the Armistice was signed restrictions were imposed which prevented railroad transportation of phosgene liquefied in cylinders. Uses for war gases in peace times have been sought. The author has found several solvents for the gaseous phosgene, among them gasoline, benzine and ethyl acetate, which dissolve an equal weight of the poison gas at ordinary temperatures. The solutions exert practically no pressure beyond atmospheric, so may be transported with safety within ordinary closed containers. On exposure to the air the liquid and dissolved gas evaporate. The solutions offer simple means for the use of a poison gas to exterminate rats and moles. On warming the solutions in suitable vessels the phosgene is liberated and may be used in a pure form in the manufacture of certain coal tar products of color or medicinal value.

An electrometric method for detecting segregation of dissolved impurities in steel: E. G. MAHIN and R. E. BREWER. Previous work has shown that both non-metallic and metallic inclusions cause carbon segregation in steel and the hypothesis has been advanced that this is due to the steel acting to some extent as a solvent for the foreign material. If this is correct the electrode potential of the metal should be altered in the regions immediately surrounding the inclusion. It is not possible to determine this point by the usual method involving immersion of the specimen in an electrolyte but a method has been devised for exposing microscopic areas of metal surface to an electrolyte, so that the micro-electrode thus formed may be connected with a standard calomel halfelement and the E.M.F. of the system measured by the usual compensation method. This method has been applied to an investigation of the ferrite bands produced by heating steel in contact with metallic inclusions; it has been found possible thus to measure the potential of these micro-areas and to establish the fact that the ferrite of these segregated portions possesses a distinctly lower potential than the ferrite of the body of the steel. The work is being extended to include investigation of the potential of ferrite adjoining other metallic and non-metallic inclusions and it may be applied also to the detection of segregation of the constituents of non-ferrous alloys.

Soda-lime for industrial purposes: R. E. WILSON. The work to be described in this paper was an