FOODS HUMAN NUTRITION. 159 



here reported were made with a view to discovering wiiether the home prepara- 

 tion of nicotin sprays is practicable. A study made of the analvtical methods 

 is also briefly reported upon. 



In analyses made of tobacco leaves, stems, and sweepings it was found that 

 the nicotin content of stems did not fall below 0.48 per cent and was not above 

 0.609 per cent. Analyses of leaves of Virginia tobaccos gave a variation of 

 from 2.47 to 0.63 per cent nicotin. Analyses made of seven different nicotin 

 preparations are also reported. The results of laboratory work showing the 

 results of ditt\'rent method.^ of extraction follow: 



"It was found that by soaking the material overnight 70 per cent of the 

 nicotin of sweepings was extracted, while by soaking overnight and bringing to 

 boiling, 78 per cent was extracted. However, the yield of juice was diminished 

 by cooking, so that by heating to boiling, cooling, and straining, only 68 per 

 cent of the nicotin was available. Practically the same results were obtained 

 with stems as with sweepings. The stems would take up about 25 per cent of 

 the water added to make the extract, and this diminishes the yield accord- 

 ingly. ... It was found that by soaking 24 hours, 78 per cent of the total 

 nicotin was extracted, and that from 50 gal. of water used 3S| gal. of juice 

 were obtained. ... 



"At current prices for tobacco stems, sweepings, and damaged tobacco, nicotin 

 extracts can be made on the farm more economically than they can be pur- 

 chased. The chief difficulty is the impossibility (without chemical analysis, 

 which is impracticable on the farm) of standardizing the extract, that is, 

 always making it at a certain definite strength or percentage of nicotin, since 

 the nicotin content of tobacco varies according to the variety, soil, method of 

 curing, and other factors. The experiments show, however, that for all prac- 

 tical purposes tobacco decoctions can be made on the farm that are near enough 

 to the desired strength, since an excess of nicotin in the spray does not injure 

 the plants. . . . Laboratory experiments showed that the home prepared to- 

 bacco decoctions gave equally good results for killing plant lice as the proprie- 

 tary extracts. . . . When tobacco stems cost $20 i>er ton, a homemade tobacco 

 spray for aphis will cost about $1 per 100 gal., as compared with $1.20 for black- 

 leaf 40, and the stems are worth about $10 per ton for fertilizer after their 

 nicotin is extracted, since they still contain all the phosphoric acid and most 

 of the potash originally present." 



FOODS— HUMAN NUTRITION. 



Minnesota wheat investigations. — Series III, composition and quality of 

 spring' and winter wheats, crops of 1912 and 1913, C. H. Bailey (Minucsota 

 ^^t(i. BuJ. IJfS {lOlJ/), PI). 5S, figs, .'i).— This bulletin reports the results of inves- 

 tigations of Minnesota wheats which were carried out in continuance of those 

 previously reported (E. S. R., 29, p. 202). In these investigations studies were 

 made of the hard winter and spring wheat crops of 1912 and 1913. Analyses 

 and studies of the milling quality of the wheats and of the baking qualities of 

 the flour produced from them were made for the purpose of comparing different 

 types and varieties of wheat grown under varying conditions and to study the 

 relation between environment and composition and quality of the wheats. The 

 results of this investigation may be summarized briefly as follows: 



" The average quality of the spring wheat samples of the crop of 1912 was 

 inferior to that of the crop of 1911 so far as protein content and baking strength 

 were concerned. The kernels were plumper, however, and yielded higher per- 

 centages of flour. The samples of the 1912 crop grown in the northwestern 

 section were generally superior in baking quality to those grown in the same 



