311 



used for the separation of tobacco seeds, in tlie experiments on tobacco 

 breeding pei'formed at tlie Connecticut State Experiment Station. This 

 apparatus is described in tlie Yearboolv of the Department of Agriculture 

 for 190i. Sliglit modifications were found necessary to adapt it to this 

 t>pe of seed. A number of seeds fi'om both the heavy and light portions 

 wore accurately weighed. The average of the light seeds was 0.0035 

 grams and of the heavy 0.0084, a ratio of 1 :2.40. Tlie variation in the 

 lieavy seeds was from 0.0077 to 0.0091 grams and in the light from 0.0017 

 to 0.0046. The greater variation in the light seeds was found to be due 

 to the force of the air current employed in the separation. That a sep- 

 aration into light, medium and heavy can be made just as readily as into 

 light and lieavy will be shown in connection with another form. 



A planting of three acres of burdocli of the present year has been 

 clioseu as a type upon which to calculate the increase in yield which 

 might have been obtained by means of seed selection. This planting was 

 made upon a deep mellow loam and the total yield of 33,890 pounds is 

 rather uiiusvial. Assumijig that the seed supply used on this planting con- 

 sisted of light and heavy seeds in the determined proportion of 1 :2.0, the 

 total yield can be theoretically divided into two portions of 6,778 and 

 27,112 pounds, respectively produced by the light and heavy seed. Had 

 ihe light seed used been equal in weight to the heavy seed they would 

 have produced twice as much as they theoretically did, whicli would have 

 been ISj.loG pounds. Tliis would make a total yield of 40,668 pounds in- 

 stead of 33,890, an increase of 20 per cent. 



Even of greater importance, however, to the medical and pharma- 

 ceutical professions is the improvement of henbane and digitalis, repre- 

 senting as they do two valuable drugs of the United States Pharmacopfpia. 

 P-.\ their being more amenable to chemical and physiological methods of 

 siandardization, the investigator is furnished with additional means of 

 following the progress of various methods of improvement. Official hen- 

 bane is supposed to consist of the dried leaves and flowering tops of 

 llyoscyamus niger L. collected from plants of the second year's growth 

 and yielding not less than 0.08 per cent, of mydriatic alkaloids. That the 

 above chemical and botanical conditions of this drug rarely obtain has 

 been clearly demonstrated. An average of a large number of samples 

 examined from August 25, 1908, to September 23, 1911, indicates that only 

 13 per cent, conformed to the requirements of the United States Pharma- 



