NA TURE 



[August io, 1905 



being limited, preference is given in the purchase of foreign 

 worl-is to the departments of hi^tory, letters, and the 

 arts, these being the subjects in which the librarians them- 

 selves have special interest and knowledge. Important 

 scientific books are thus often overlooked. The current 

 books of reference and the principal foreign journals are 

 difficult of access, and are not at hand for immediate 

 use : journals are often not available for a year, or more, 

 after the date of issue owing to their being sent to the 

 binders. For these reasons, and on account of the time 

 wasted in waiting and formalities, the principal libraries 

 are hardly used at all for scientific purposes by most of 

 the workers engaged in active research. The professors 

 and teachers of Paris consider that the special libraries 

 attached to the actual laboratories are more valued and 

 are of greater use than the larger and more general 

 libraries, and that these should be coordinated so as to 

 be available for any properly accredited worker. On the 

 other hand, there seems to be a desire on the part of the 

 Government to limit the usefulness of these actual work- 

 ing libraries by reducing the grants formerly allotted to 

 them. Some of the criticisms of the Paris libraries and 

 suggestions for their amelioration are not without applica- 

 tion in this countrv. 



SOCIETIES AND ACADEMIES. 

 London. 



Royal Society, May 15. — " Conttibmions to the Physiology 

 of Mammalian Reproduction. Part i.. The Oistrous Cvcle 

 in the Dog. Part ii., The Ovary as an Organ' of 

 Internal Secretion." By F. H. A. Marshall and W. A. 

 Jolly. Communicated by Prof. E. A. Schiifer, F.R.S. 



The experiments lead to the conclusion that the ovary 

 is an organ providing an internal secretion which is 

 elaborated by the follicular epithelial cells or by the inter- 

 stitial cells of the stroma. This secretion circulating in 

 the blood induces menstruation and heat. After ovulation, 

 which takes place during oestrus, the corpus luteum is 

 formed, and this organ provides a further secretion the 

 function of which is essential for the changes taking place 

 during the attachment and development of the embryo in 

 the first stages of pregnancy. 



June 8. — "Researches on E.xplosives." Part iii. By 

 Sir Andrew Noble, Bart., K.C.B., F.R.S. 



The principal object of the researches which are com- 

 municated in this paper was to ascertain, with as much 

 accuracy as possible, the differences in the transformations 

 which modern e.\plosives suffer when fired under gradually 

 increasing pressures. The first part of the paper gives a 

 description of the varied apparatus employed. 



.Although the author has made experiments with many 

 other explosives, those examined in this paper are three 

 in number: — (i) Cordite; (2) the cordite known as M.D. ; 

 and (3) a tubular nitro-cellulose. 



The modes of observation and calculation followed are 

 described, and then in tabular form arc given the results 

 of the series of experiments on the three explosives named. 

 These tables being too extensive to reproduce in full, the 

 results of the experiments at the lowest and highest 

 densities alone are given : — 



nc 



ily of charge exploded. 



Pressure in tons per square inch. 

 2-9 52-9 I 2-7 43-22 I 3-35 40-5 



Pressure in atmospheres. 

 442-1 S063-S I 411-6 65S7-3 I 510-7 6173-6 



Units of heat. 

 1272-3 1360-0 I 1035-9 



',./.■. fluid. 

 iigo-o I 896 I 



1036-9 



NO. 1S67, VOL. 72] 



I nits of heal, 'oater gaseous. 

 1186-8 1287-0 I 961-9 I132-5 I 829-2 977-7 



Specific heat. 

 0-23040 0-223S5 I 0-23714 0-22529 I 0-23772 o 22828 



Temperatures of e.-cplosion. Centigrade. 

 5i5r-i 5749'-4 I 4056'-2 5026^-8 | 3488''-i 42S2°-9 



Comparative potential energy. 

 0-9S25 i-oooo I 0-8401 0-8S42 I 07389 0-7686 



If the figures given in these tables be carefully examined, 

 it will be observed that for the three explosives the trans- 

 formation on firing appears, in all, to follow the same 

 general laws. 



Thus in all three there is, with increase of pressure, at 

 first a slight increase, afterwards a steady decrease, in the 

 volume of permanent gases produced. 



In all three explosives there is, with increased pressure, 

 a large increase in the volume of carbonic anhydride, and 

 a large decrease in the volume of carbonic monoxide. In 

 the volume of hydrogen this decrease with increase of 

 pressure is very great ; while methane, the percentage of 

 which with low pressures is quite insignificant, very 

 rapidly increases, and at the highest density is from twenty 

 to thirty times greater than at the lowest density. 



There are some variations in the percentages of nitrogen 

 and water vapour, but on the whole these constituents 

 may be considered to be nearly constant. 



The units of heat developed show with increased pressure 

 a slight decline at first, but afterwards increase somewhat 

 rapidly at the higher pressures. 



In the tables submitted it w-ill be observed that the 

 specific heats and the temperatures of explosion have been 

 given, but with respect to temperatures so far above those 

 in regard to which accurate observations have been made 

 the figures given can only be taken as provisional. 



These temperatures have been obtained by dividing the 

 units of heat (water gaseous) by the specific heats ; 

 although provisional, they can safely be used in com- 

 paring the temperatures of explosion of the three explosives. 



The comparative approximate potential energies are 

 obtained by multiplying the volume of gas produced by the 

 temperature of explosion. The means for the three 

 explosives are respectively: — cordite, 0-97(12; M.D., 0-8387; 

 nitro-cellulose, 07464. The highest potential energy (taken 

 as unity), it will be noted, was obtained from cordite at a 

 density of 05. 



It is submitted that the wide differences in the trans- 

 formation of the three explosives with which the experi- 

 ments have been made justify the general conclusion at 

 which Sir F. Abel and the writer arrived in the year 1874 

 (Transactions of the Royal Society, vol. clxiii. p. 85) with 

 respect to gunpowder, viz. that any attempt to define by a 

 chemical equation the nature of the metamorphosis which 



