February 26, 1886.] 



SCIEXCF. 



187 



caskets are designed to preserve the body in nearly 

 a natural state by excluding the air. The body is 

 surrounded with ground cork, and the lid of the 

 casket is carefully cemented with white lead ; it 

 is then wrapped in a layer of thick felt, and placed 

 in a tightly constructed pine case, which is com- 

 pletely filled with the ground cork. The seams of 

 the pine box are carefully covered with white 

 lead, and the whole is enveloped in another thick 

 wrapping of felt ; over the latter is a covering of 

 burlap, secured by stout cords ; outside is a pine 

 crate. These caskets are believed to be the best 

 ever made for the preservation of the dead ; and 

 the great success achieved in the transportation of 

 the remains of De Long and his companions would 

 seem to indicate their entire feasibility for general 

 use in similar instances, or where bodies are to be 

 transported long distances through many climatic 

 changes. 



— The herbarium of the national museum at 

 Washington now embraces over 25,000 specimens, 

 representing 17,000 species, and is established upon 

 a broad basis, which admits of almost unlimited 

 expansion. The North American flora is repre- 

 sented by about 7,000 species, contributed by Ward, 

 Canby, Havard, and others, and is constantly in- 

 creasing. The herbarium is also rich in European 

 species, the gift for the most part of the authori- 

 ties at Kew, and chiefly from the collections of 

 George Curling Joad and J. Gay. This material, 

 however, represents only a small portion of the 

 national herbarium, the greater part of which is 

 yet at the department of agriculture, where the 

 government collections were formerly deposited 

 before the erection of the national museum build- 

 ing. Case-room is provided, and the specimens 

 are permanently mounted and systematically ar- 

 ranged according to the system adopted by Ben- 

 tham and Hooker in their 'Genera plantarum.' 

 The collection is rendered easily accessible by means 

 of a card catalogue, and Roman and Arabic label 

 numbers for order and genus on each genus-cover. 

 The herbarium is placed in immediate connection 

 with the department of fossil plants, and under 

 the same curatorship. It is intended that all 

 duplicate material shall represent either additional 

 parts of plants or widely different localities, as 

 illustrating their geographical range, local varia- 

 tion, etc. Other duplicates will, however, be 

 utilized in effecting exchanges for species not 

 represented. 



— The Berichte der deutschen botanischen gesell- 

 schaft contains the interesting results of a number 

 of experiments recently made by Strasburg upon 

 the grafting of solanaceous plants. Jimson-weed 

 (Datura stramonium) and 1 wintercherry ' (Physalis 



alkengi) were ingrafted upon potato-stocks, with 

 immediate union ; and with the tobacco-plant less 

 speedy though equally successful results were 

 derived. Grafting deadly nightshade (Atropa bel- 

 ladonna) and henbane (Hyoscyamus niger) was 

 accomplished with more difficulty. Other attempts 

 also succeeded in ingrafting the potato upon the 

 nightshade (Solanum nigrum), tobacco, and win- 

 tercherry, though with less ease. Not only were 

 union and growth secured between these different 

 solanaceous plants, but also between the potato 

 and Schizanthus Grahami, a Chilian scrophula- 

 rian plant, upon which the potato-fungus grows. 

 The development in this last, however, was feeble. 

 In none of these experiments did there appear to 

 result any modifying influence upon the stock. 

 The potato produced tubers as usual, though there 

 appears to have been a greater number of irregular 

 forms. With the jimson-weed the tubers were 

 well developed, but no seeds were produced. On 

 the other hand, tobacco-plants fructified abun- 

 dantly, with only a sparse growth of tubers. 

 Eeserve material does not seem to be sufficient 

 to admit of. both seeds and tubers together. 

 Potato-plants grafted on others seemed to pos- 

 sess a superabundance of reserve material, how- 

 ever, resulting in the growth of tubers of the size 

 of a walnut, in the axils of the leaves. The 

 'eyes' of these tubers, it is interesting to state, 

 developed leaves of considerable size. This growth 

 of tubers above ground has been previously ob- 

 served in the potato-plant, where the stem had 

 been crushed close to the surface. 



LETTERS TO THE EDITOR. 



**♦ Correspondents are requested to be as brief as possible. The 

 writer's name is in all cases required as proof of good faith. 



Sea level and ocean-current. 



According to Zoppritz, the winds were thousands 

 of yer;rs in overcoming - the inertia of the water, and 

 causing the present ocean-currents. Of course, dur- 

 ing the latter part of this long period, after their 

 effect had extended down to the bottom of the ocean, 

 a part of their force was spent in overcoming the 

 friction over the bottom, and toward the last a very 

 small part only in accelerating the motion. But ac- 

 cording to the same authority, after 239 years, while 

 the whole force of the winds was spent upon the iner- 

 tia of the water, only one-half the surface velocity 

 was communicated to the stratum at the depth of 100 

 metres ; and so at the depth of a few hundred metres 

 there was yet very little velocity. The greatest sur- 

 face velocities in the open sea, supposed to be due to 

 the winds, are, on the average, not more than ten 

 miles per day. The whole amount of momentum, 

 therefore, caused by the action of the winds, is only 

 about equal to that of a stratum 100 metres in depth, 

 with a velocity of ten miles per day, the amount of 

 momentum below 100 metres in depth being about 

 necessary to reduce that above 100 metres to the mo- 



