MICHIGAN ACADEMY OF SCIENCE. 227 



inches of the fibrous roots attached. No diseased or decrepit stems or roots 

 were talien. Three-liundred-gram samples were taken at random tliroughout 

 the colonies and were air-dried to constant weight in a warm room. They 

 were then ground to pass a 60-mesh sieve and transferred to tightly stoppered 

 bottles. The mill was carefully washed with 85 per cent alcohol before and 

 after grinding each sample, to free it from resin which collected on the huhrs 

 to a noticeable extent in some samples. Rhizomes of colony three were smaller 

 and easier to grind than those of the other colonies. 



Hygroscopic moisture of the air-dry samples was obtained with two-gram 

 samples at 98° — 100° C, and the percentage calculated to air-dry basis for 

 convenience in comparing percentages in the air-dry or crude drug condition 

 (Table 1). For ash determinations one-gram samples were heated in a muffle 

 for 45 minutes and calculated to air-dry drug. (Table 2). The nitrogen was 

 estimated by the official Gunning-Cooper ^ method with one-gram samples and 

 calculated to air-dry drug. 



SOIL ANALYSES. 



While the soils of the three colonies were essentially the same in origin 

 (Knox Silt Loam)' it was nevertheless considered desirable to determine the 

 "acidity" (lime requirement per 6-inch aci-e), total nitrogen, total volatile 

 matter, and total moisture in order to enable us to detect any wide differences 

 in growth which could be referable to the soil factor. An example of average 

 conditions found is incorporated in Table 3. 



The methods and data are here given very briefly, since the differences in 

 data are considered to be insufficient to cause any noticeable effect in the 

 gi'owth of these colonies. 



Total moisture and volatile matter were determined on 5-gram samples of 

 well mixed samples and calculated to oven-dry basis. 



After drying to constant weight at 99° — 100° C. and noting loss in weight, 

 the samples were ignited to redness for one hour in a muffle, and after cooling 

 in a dessicator were again weighed and loss noted and calculated to oven-dry 

 basis. After ignition, the soil had a bright red color throughout, whereas its 

 natui'al color is a yellowish brown or gray if fertile. Total nitrogen was deter- 

 mined by the official Kjeldahl •* method, modified to include nitrates, one-gram 

 samples being used and amounts calculated to pounds, in a G-inch acre. 



These soils were slightly acid to litmus, and this was confirmed by deter- 

 mining the amount of tenth-normal potassium hydroxide required to neutralize 

 100 grams of soil after being shaken three hours with 250 c. c. of normal 

 potassium nitrate, according to the method used by Hopkins and Pettit."* As 

 noted in Table 3, the acidity was slight (200-300 pounds of lime per (5-inch acre 



^U. S. Department of Agriculture, Bur. of Chemistry, Bull. 107 (revised). 

 ^Tippecanoe County (Ind.) Soil Survey Map, Bur. of Soils, ini.'i. 

 ■•U. S. Department of Agric, Bur. of Chemistry, Bull. 107 (Revised): 

 '^Hopkins, C. G., and Pettit, J. II. Soil Fertility Laboratory Manual. Ginn & 

 Co., 1910. 



