OCTOBEK T, 1910] 



SCIENCE 



479 



regarded as the chief organisms which spoil corn 

 in such a way as to cause it to produce pellagra 

 when consumed by badly nourished, wretchedly poor 

 peasantry living under poor hygienic conditions. 

 It has been reported by a number of Italian in- 

 vestigators that these moulds pi-oduce toxic sub- 

 stances, and it is believed that these substances 

 are phenol acids. This belief is based not upon 

 the isolation and identification of these sub- 

 stances, but upon the fact that extracts of the 

 cultures gave red or violet colors with ferric 

 chloride. Howeverj not all investigators have 

 been able to obtain toxic extracts from cultures, 

 or extracts giving a positive reaction with ferric 

 chloride. Hence, the whole question whether or 

 not Penicillium produces toxins when growing 

 upon corn, and whether or not this organism has 

 anything to do with the production of pellagra, 

 is still unsettled. 



It has occurred to the authors that the dis- 

 crepancy in the results obtained by various in- 

 vestigators may possibly be due to the fact that 

 the organisms which each investigator studied 

 may not have been identical, v'ery recently there 

 has appeared from the department of agriculture 

 a publication by Thom,' in which for the first 

 time the fungi of this genus have been adequately 

 studied from the systematic point of view. It is 

 therefore now possible to investigate each species 

 separately. The authors are engaged upon the 

 investigation of the biochemistry of different spe- 

 cies of Penicillium which have been obtained from 

 Thom, and which Br. Erwin F. Smith has been 

 kind enough to grow. Great differences have been 

 found in the products of five of the species in- 

 vestigated so far. Of these five but one gives a 

 positive ferric chloride reaction, and the toxicity 

 of the extracts varies greatly for the different 

 species. The authors are engaged upon a detailed 

 study of the products produced by these organ- 

 isms, of the relative toxicity, and of the nature 

 of the substance which is responsible for the 

 ferric chloride reaction. It is hoped that this 

 preliminary report may soon be followed by a 

 detailed publication in which these other points 

 will be definitely cleared up. 



Field Tests with Plant Foods, Malerials and Re- 

 sults: H. A. Huston. 



In the winter wheat section of the United 

 States, commercial plant foods are very profitably 

 used, while the reports of most of the plot tests 



' U. S. Dept. Agri., Bureau Animal Industry 

 Bull. Xo. 118. 



at experiment stations indicate that they are un- 

 profitable. Some reasons for this apparent con- 

 flict are pointed out, special reference being made 

 to necessity of using materials free from sub- 

 stances like the gypsum contained in acid phos- 

 phate and the sodium in nitrate of soda capable 

 of producing indirect effects, to the desirability 

 of using suitable methods of application, proper 

 amounts of materials, and reasonable interpreta- 

 tion of results. 



The Negative Influence of Soils upon the Nitro- 

 gen Content of Wheat: G. W. Shaw. 



In connection with another research the an- 

 alytical results of which have been published in 

 Bulletin No. 128 of the bureau of chemistry, 

 department of agriculture, experiments have been 

 conducted to difi'ereutiate between the climate 

 and soil factor upon the protein content of 

 wheat. 



In 1907 until the present season the writer has 

 undertaken to neutralize one of these factors, 

 viz., climate, by securing from Hays, Kans., a 

 plat of soil 6X3X3 feet which for a long 

 period had produced high protein wheat, and the 

 preceding season produced wheat carrying 20.06 

 per cent, of total protein. A quantity of this 

 wheat was also obtained at the same time. 



The soil was removed from its original position 

 in six-inch layers and brought to California, 

 where it was placed alongside of a plat of Cali- 

 fornia soil prepared in a similar manner, each of 

 the holes having been first lined, except at the 

 bottom, by a loose cement lining. 



On one end of each of these plats was grown 

 in 1907-8 wheat from the original high-protein 

 wheat from Kansas, and on the other end a hand- 

 selected low-protein durum wheat. By this soil 

 transfer it was intended to neutralize the effect 

 of climate and to have as a variable factor only 

 the soil. 



In physical character each of the soils would 

 be classed as silt loams. Chemically there was 

 essentially no difference in the top foot, which 

 held particularly true in the essential elements 

 of plant food. In the other two feet the main 

 difference lay in the nitrogen content, this being 

 the greater in the California soil, thus giving it 

 a slight advantage in this respect. The detailed 

 analyses are presented in tabular form. 



In the first season the grain produced from the 

 low-protein original increased by about 4. .5 per 

 cent, on each of the two plats, there being a 

 difference of only 0.07 per cent, total protein 



