FORESTRY. 443 



source of the potash. As coiuparetl with kaiuit, muriate of potash aud sulphate 

 of potash as sources of i)()tash gave a growth perfortuance of ouly 00 i)er cent. 

 The use of a fertilizer without potash, however, iudicated that the soils upon 

 which the seedlings were grown were only slightly deficient in potash, since in 

 this case a growth yield of 89 per cent was obtained. 



Lime used in conjunction with the original soil cover, the latter being incor- 

 porated into the seed bed to a depth of 10 in. gave a gi-owth yield of ouly 55 

 per cent. When lime was used alone the growth yield was ouly 30 per cent. 

 A growth yield of 42 per cent was obtainetl where the soil cover was incorpo- 

 rated without any other fertilizer as compared with a growth yield of 33 per 

 cent where the soil cover was removed and no fertilizer used. 



On the influence of cultural methods on the yield of the common pine, 

 M. KuNZE {Tharand. Forstl. Jahrh., 59 {1909), No. 1, pp. 1-26). — In continua- 

 tion of previous thinning and wood volume investigations to which reference 

 is made in the article, some further measurements are given which were taken 

 at the time of the sixth thinning of some experimental pine stands iu Saxouy, 

 and which were designed to show the effect of various cultural treatments on 

 the yield of the pine. 



Properties and uses of the southern pines, H. S. Betts (77. S. Dept. Agr., 

 Forest Serv. Circ. 164, PP- 30, figs. 6). — This circular contains au account of the 

 southern pines relative to their nomenclature, botany, distribution, enemies, 

 physical and mechanical properties, and utilization. The results of several 

 mechanical tests of structural material and of small pieces are given, consider- 

 able of the data being based upon previous publications of the Forest Service 

 (E. S. R., 9, p. 842; 19, p. 051). 



Experiments on the effect of the soil of the hemlock grove of the New 

 York Botanical Garden upon seedling's, Winifeed J. Robinson {Jour. N. Y. 

 Bat. Gard., JO {1909), Xo. 112, pp. 81-87, fig. i).— The data are given of a 

 series of experiments conducted for the past 3 years in the New York Botan- 

 ical Garden to determine whether any chemical constituent of the soil in the 

 hemlock grove was the detrimental factor causing the commonly noted failure 

 of hemlock seedlings to develop. From the data secured it appears that the 

 failure of the seedlings to germinate beneath the adult trees is not due to a 

 special toxic constituent of the soil, but rather to such factors as the amount 

 of moisture and light and to the physical condition of the soil caused by the 

 mat of hemlock needles that accumulates beneath the trees. 



Paper birch in the Northeast, S. T. Dana ( U. S. Dept. Agr., Forest Serv. 

 Circ. 163, pp. 37, figs. 2). — An account is given of the paper birch {Betula fiapy- 

 rifera) relative to its importance and uses, distribution aud supply, botanical 

 and silvical characteristics, methods of lumbering and systems of management 

 together with a map showing the distribution of paper birch iu commercial 

 quantities in the Northeast, aud several diameter, volume and yield tables based 

 on measurements of a large number of trees. The author concludes that under 

 prevailing forest conditions the supply of paper birch will not be exhausted 

 for a good many years. 



The tree-cotton or kapok tree (Eriodendron anfractuosum), M. MiJCKE 

 {Pflanzer, 7/ {1908), Nos. 19, pp. 289-300; 20, pp. 305^19).— An account is given 

 of this tree i-elative to its botany aud culture, the harvesting and preparation 

 of kapok cotton and kapok oil, the microscopical, chemical, aud physical proper- 

 ties of these products, the uses of kapok, its adulteration, yields, prices received, 

 and other statistics of the industry. A bibliography of this si)ecies is ai)peuded. 



The balata industry in Surinam, D. Fock {De Balata-industric in Surinamc. 

 I'artiinaribo. [ 1909 \, pp. \ + i;i) + CI\ +67+98, dgm.l).— In part 1 of this book are 

 brought together a number of government reports of various dates making as a 



