412 



NATURE 



[January 23, 1919 



mental facts and constants, the development oi theory, 



and tin- (-[alili-.lun.-iu of general principles. Research 

 must be given greater prominence a1 such institutions 

 to 1 nable industr) to recruit the proper type of worker 

 for its own research problems. Ii is desirable to 

 provide technical schools with more experimental plant 

 mi an industrial scale, so that students from the 

 schools will be able ai once to appl) their research 

 method-, to the requirements of the industrial firm 

 which the) enter. In conclusion, Mr. Little em- 

 phasised the importance oi creating an interesl in 

 research problems in the mind of the manufacture] 

 and the public. 



I'm 111, in r886, pointed out thai while d-asparagine 

 is sweet, its stereo-isomer, I-asparagine, is tasteless. 

 This was the first observation indicating the nature 

 of tin connection which may exist between the flavour 

 and the molecular structure or configuration of an 

 organic compound. Since that time a large number 

 ni records have been made as to the effect which 

 changes in chemical composition or molecular ar- 

 rangement bring about in the flavour of organic sub- 

 stances. Thus ./-limine and [/-phenylalanine have 

 been found to be sweetish, whilst their laevo-isomers 

 are bitter; and of the anisaldoximes the one with the 

 owtt-configuration is very sweet, whereas the syn- 

 aldoxime i» tasteless. The monohydric alcohols are 

 only slightly sweetish, but with increase of the number 

 of hydroxy! groups, as in the glycols, glycerols, etc., 

 the sweetness becomes verj marked. On the other 

 hand, the strong sweet taste of "saccharin" is 

 destroyed bj relativel) slight molecular transforma- 

 tions, such as the replacement of an imide hydrogen 

 atom by a methyl or ethyl group. In the Revue 

 Scientifique for December 7, iqiS, MM. Barral and 

 Ranc give an interesting summary, ten pages in 

 length, describing the present state of knowledge 

 respecting what may In railed the chemistry of sweet 

 flavours. In fine, the known facts, they consider, 

 resolve themselves into a series of approximations to 

 generalisations, but there are always exceptions or 

 anomalies. \\Y are, indeed, still very far from being 

 able to establish a general law, such as would enable 

 the flavour of a compound to be deduced when its 

 molecular structure is known. 



CrtrnF. a-trinitrotoluene, the high explosive, is liable 

 to contain small quantities of its /3- and y-isomers. 

 The three substances are very similar in physical pro- 

 pertii s, and are equally powerful as explosives. Al- 

 though the a-variety is by no means a sensitive explo- 

 sive, some accidents have occurred with it which have 

 not been satisfactorily explained, but which have indi- 

 cated tiiaf ll" substance may sometimes contain a 

 much more sensitive body. It has generally been 

 supposed thai lb.- latter is derived from a-trinitro- 

 toluene, but it may equally well be derived from the 

 the -,-isomer. Messrs. Ryan and O'Riordan 

 (Proceedings of the Royal Irish Academy, December) 

 give an ai.. uint of an investigation which they have 

 carried oul in order to elucidate this question. In the 

 course ..! their work they found that a sample of crude 

 •/-trinitrotoluene contained a dark, amorphous sub- 

 stance which explodes on heating; this, they think, 

 may he of considerable interest in connection with 

 the explanation of the accidents mentioned. 



Dk. Sidney i ;ests a new X-ray unit in 



radiotherapy. The unit, termed a "rad," is based 

 ,m the amount of radium which, when applied to 

 malignant tumour cells, causes complete inhibition of 

 their power to grow after an exposure for one hour; 

 this is determined by tests on rat-cancer. For measur- 

 ing the dose of X-ravs administered to a patient, the 



NO. 2569, VOL. I02] 



photographic action of the rays is obtained on a photo- 

 graphic plate, and Upon the same plate is impressed 

 tin photographic action of the standard radium. The 

 plati 1- developed and a comparison made between 

 the photographic impressions so obtained. For 

 example, if the X-ray tint for an exposure of ten 

 seconds equalled that obtained with an exposure cf 

 six seconds with the radium, the dose of X-rays 

 during the ten seconds' exposure would be 1/600 rad 

 ( [r chives of Radiology ma/ Electrotherapy, No. 221, 

 918, p. 226). 



Iim launch of the first large self-propelled sea- 

 going reinforn d-concrete vessel to be built in Great 

 Britain -the Armistice — took place at the Ferro-Con- 

 crete Ship Construction Co.'s yard at Barrow-in- 

 Furness en January 7, and forms the subject of an 

 illustrated article in Engineering for January to. The 

 ship is of 205 ft. length between perpendiculars, 32 ft. 

 moulded breadth, 19 ft. () in. moulded depth, and is 

 to have a speed of about yf knots with 400 indicated 

 h.p. Trisec steel bars having a very high tensile 

 strength were used for the reinforcement. The con- 

 crete was made up of a granite aggregate, sand, and 

 British standard specification cement. The sand used 

 was a mixture of coarse and fine grains, from $ in. 

 downwards; the aggregate consisted of granite chip- 

 pin-s of assorted sizes, not less than \ in. and not 

 more than I in. Fresh water was used exclusivelv 

 for mixing up the concrete. The. method used in 

 construction was to build a box round the reinforcement 

 bars, info which the concrete was poured and rammed 

 hard. To reduce the quantity of timber employed a 

 system of steel sheets, suitablv stiffened, was used as 

 shutters. The machinerv consists of two cylindrical 

 boilers q ft. 6 in. in diameter by q ft. long, to work at 

 140 lb. per sq. in. The engines are of the compound 

 surface condensing type, having cvlinders 15A in. and 

 33 in. in diameter by 24 in. stroke. 



In the Tim'fis of January 14 there appears .n\ 

 interesting account of the surrendered German ship- 

 by a member of the Allied Naval Commission in 

 German waters. The good German shooting is attri- 

 buted more to superior range-finders and training than 

 to the gunnery control system. The statement that 

 the German ships unquestionably had more accurate 

 range-finders than the British is not accepted by many 

 of those in possession of the facts. It is generallv 

 agreed that the first German salvoes were excellent, 

 but not necessarily better than the British, and that, 

 whereas the British lire continued good, the German 

 fire became erratic when the ships were hit. Tin 

 primary function of a Service range-finder is to pro- 

 vide ranges when in action. It is essential that it 

 should keep in adjustment under battle conditions. 

 To save the reputation of the German range-finder it 

 is necessary to attribute the failure to a peculiar 

 human moral weakness, which, however, was cer- 

 tainly not in evidence throughout the war. As the 

 result of the Battle of Jutland the superiority of 

 British lire was recognised by the Germans, whose 

 later conduct is some proof of this. The superiority 

 of British range-finders was known to the German 

 Government, which in 1014 approached British 111. 

 with regard to the supply of their instruments. 

 During repeated competitive trials by the French 

 Government the German range-finders were invari- 

 ably beaten by the British. This defeat the Germans 

 explained on political grounds, but as the result of 

 extensive trials in Austria-Hungary British instru- 

 ments were adopted throughout the. Austro-Hungarian 

 Navy and largely throughout the Army. These British 

 range-finders which have defeated the German product 

 in so many lands have optical parts made of British 



