162 Scientific Intelligence. 



in the arts as viscose, has commanded a good deal of attention 

 on account of its applications to certain phases of textile indus- 

 try, notably the dressing of cloth and the manufacture of an 

 imitation of silk. The present volume is a convenient appendix 

 to the former one, and brings together not only the rejoinders 

 which the authors have made to some criticisms of their earlier 

 work, but also some of the more important contributions to the 

 subject of paper-pulp and the deterioration of paper. Chemists 

 and botanists will be interested especially in the pages devoted 

 to the constitution of cellulose or, rather, of the celluloses. The 

 industrial applications of cellulose, although briefly treated, are 

 presented in a manner calculated to stimulate further research. 



G. L. G. 



5. The Memorial Greenhouses at the Harvard Botanic Garden 

 have an attached laboratory for certain lines of study in vege- 

 table physiology. The buildings were erected specially with the 

 design of giving ample accommodation for four or five advanced 

 students, and an additional greenhouse, close by, is devoted to 

 the use of a large class of elementary students of plant physiol- 

 ogy. In the memorial building, the present equipment affords 

 facilities for carrying on investigations in regard to the relations 

 of plants to electricity. Use is made of currents supplied by 

 the city electric company, not only for constant lighting, but 

 also for experiments in connection with soil. Through suit- 

 able reduction of the voltage, provision is made for many sorts 

 of apparatus required in the study of the effects of different cur- 

 rents upon plants. A set of speed-reducers connected with the 

 motor gives wheels of all desired rates for clinostat observations 

 of movements in all planes. 



At present, researches are in progress by Mr. Plowman in 

 regard to the behavior of plants in the magnetic field, and also 

 when under the influence of weak currents of electricity. Mr. 

 Jenkins is now working on the condition of roots in soil through 

 which are passing currents strong enough to cause electrolytic 

 action on gas- and water-pipes ; Mr. Stickney is continuing studies 

 in regard to the effects of certain poisons on plants, and Mr. 

 Poole has in hand experiments of a novel character relative to 

 the activities of plants in a saturated atmosphere. Mr. Miller is 

 now closing his series of experiments in regard to the effects of 

 a top layer of very fine soil upon the soil beneath. It has been 

 claimed that such a layer of fine soil conserves the water in the 

 soil under it, to such an extent as to warrant the employment of 

 pulverizers in arid or semi-arid districts. The loss of moisture is 

 unquestionably checked by this so-called "blanket" of dust, but 

 Mr. Miller shows that the cover of dust must be practically 

 pulverulent throughout in order to make it effective. The 

 " caking" of the dust-cover, even if very slight, after a few drops 

 of water have fallen on it, reduces greatly the efficiency of the 

 protection. g. l. g. 





