July 29, 1909I 



NA JURE 



'0/ 



made a close study of the flora of Venezuela. The list 

 comprises about 650 species, of which two-thirds are 

 common to tropical America, thirty-seven are west Indian, 

 and eighty-two are confined to South America, of which 

 one-half are endemic. The Legumlnosje is the pre- 

 dominant family, and supplies many of the common plants, 

 such as species of Csesalpinia, Cassia, and Calliandra. 

 The family of Cactacese is individually, although not 

 specifically, well represented, and the species of Bromeli- 

 acea; are conspicuous on account of their striking colours 

 and appearance. The paucity of species in comparison 

 with the number of genera is marked, the proportion 

 being i-6 to i ; the specifically largest genus is Croton, 

 with eleven species ; Capparis provides nine species. 



Messrs. B.\usch .and Lome, Thavies Inn, the makers 

 of the high-class Minot microtomes, have issued a new 

 catalogue of their various patterns to indicate recent 

 improvements. Additional features are noted for the well- 

 known Minot automatic rotary microtome ; the knife can 

 be moved to and fro, from side to side, or can be rotated, 

 owing to its insertion in a special knife block ; split nuts 

 with releasing lever allow of rapid adjustment, and the 

 feed wheel is provided with a guard. The new model 

 Minot automatic precision microtome, a powerful and 

 rigid type designed for heavy work, although equally 

 efiicient for light cutting, has been re-modelled ; the gear- 

 ing between fly-wheel and crank produces an exceptionally 

 smooth feed. A freezing microtome for fixing on the 

 nozzle of a cylinder containing carbon dioxide is a new 

 instrument, intended to provide surgeons with an apparatus 

 for preparing sections that can be examined on the spot. 



We have received the Studi e ricerche di chimica agraria 

 for the years 1906-8 from the agricultural chemistry 

 laboratory of the University of Pisa. The volume includes 

 a paper by the director. Prof. Italo Giglioli, on the 

 stimulus to plant growth occasioned by small quantities of 

 manganese salts, &c., and studies by A. Quartaroli on 

 certain properties of phosphates of agricultural interest. 



A SUBJECT of great practical importance and scientific in- 

 terest is discussed in a recent issue of the Cairo Scientific 

 Journnl (No. 29). For the past twelve years there has been 

 « steady fall in the average yield of Egyptian cotton per 

 feddan, and the loss now amounts to five pounds per feddan 

 per annum at current prices. The late Mr. Gibson, in 

 iqo6, attributed the loss to the rise in level of the subsoil 

 water, which is a direct consequence of the canal 

 system now being introduced. One case was noted on 

 the Slate Domains where a high-level canal raised the 

 water-table of the adjoining land by seepage from a depth 

 of 3 metres to lA metres, and the yield of cotton fell off 

 considerably. The remedy appears to lie in a great 

 extension of the drainage system. 



Attention has recently been directed in the pages of the 

 North British Agriculturalist to the use of soya beans as 

 cattle food. The bean is well known in America and in 

 Asia, but has hitherto not been used in the British Isles. 

 After removing some of the oil, the residue is made into 

 oil-cake containing about 7 per cent, of oil and 40 per cent, 

 of " albuminoids " (i.e. 6'4 per cent, of nitrogen, albumi- 

 noid being defined as nitrogen X 6"25), and is at present 

 cheaper than other foods of like composition. During the 

 spring of this year about 50,000 tons of beans have 

 been imported, it is understood, from Manchuria, and at 

 present prices the cake promises to form a very useful 

 addition to the list of cattle foods. 



Mr. E. S. Thomas contributes to the May number of 

 the Journal of the Cairo Scientific Society a useful article 



NO. 2074, ■^OL. Si] 



summarising the facts of the early mining industries of 

 Egypt. The gold of the desert has been worked from a 

 very early period, an ingot having been found buried with 

 a corpse of. the first dynasty, while gold-handled flint knives 

 and stone jars, the mouths of which are ornamented with 

 gold, testify to the artistic skill of the people of the same 

 period. The earliest direct references to expeditions in 

 search of gold date from the twelfth dynasty. Western 

 Asia drew large supplies of gold from Egypt during the 

 period represented by the Tel-el-Amarna letters, and the 

 records of tribute paid in the precious metal by subject 

 races show that immense treasures were at the disposnt 

 of tile Pharaohs. Silver was also received in large quanti- 

 ties from Crete, Attica, and probably from Cilicia. The 

 first systematic scheme for gold-mining under Egyptian- 

 management dates from the nineteenth dynasty,' and it 

 continued to be carried on until it became impossible to 

 protect the workers from Bedouin marauders. Large 

 workings in the quartz reefs at Um Rus and Haimur 

 show the vast extent of these operations. .-Mtogether 

 about ninety old workings in search of gold have up tc 

 the present been identified in the eastern Egyptian desert, 

 and twenty more known to exist remain to be traced. 

 Exclusive of workings in the Sudan proper, all these lie 

 between lat. 22° and 28°, that is, between Minia and the 

 Sudan border, and east of long. 33°. Many others will 

 probably be discovered in the more remote desert area. 



The Director-General of Indian Observatories has issued 

 a memorandum (dated Jime 8) on the meteorological con- 

 ditions prevailing before the south-west monsoon of 1909. 

 Past experience shows that the most important indications 

 regarding monsoon rainfall are afforded by the pressure 

 conditions in South America and the Indian Ocean, and 

 these for the past two months have been decidedly favour- 

 able, being above the normal in the former and below in 

 the latter regions. Late and excessive snowfall is un- 

 favourable to the monsoon, especially in north-west India, 

 but since April none of any significance has occurred. 

 From these and other data referred to in the memorandum 

 Dr. Walker draws the following useful inferences : — 

 (a) the general conditions are such as have, in a decided 

 majority of years, been followed by a total monsoon rain- 

 fall of more than the average amount ; (b) the indications 

 regarding the geographical distribution are by no means 

 well marked, but suggest that the outlook for the plains 

 of north-west India during the earlier part of the season 

 is somewhat less favourable than that for the field of the 

 Bay current. 



Although much work has been done on the relation 

 between the magnetic qualities of steels and their com- 

 position, we are still far from being in a position to state 

 what it is exactly which confers on a steel the property 

 of magnetic permanence. The most recent work in this 

 field is that of Mr. T. Swinden, described in the June 

 number of the Journal of the Institution of Electrical 

 Engineers. Mr. Swinden, after examining a number of 

 steels containing 3 per cent, tungsten both magnetically 

 and microscopically, comes to the conclusion that magnetic 

 permanence depends more on the constitution than on the 

 state of crystallisation of the steel. 



The July number of the Journal de Physique contains 

 Dr. Hale's address to the Soci^t^ frangaise de Physique 

 on the magnetic fields of sun-spots. By means of a very 

 careful and detailed comparison of the intensities and 

 polarisations of the doublets and triplets obtained in the 

 Zeeman experiment in the laboratory with the correspond- 

 ing effects obtained in the spectra of sun-spots by the 



