SCIENCE-GOSSIP. 



167 



species usually found in such silualions on the c^ast 

 coast. The most conspicuous and also the most 

 lieautiful was the common sea lavender (Stalitc 

 liiiwnium L. ) .Many acres of ground were linle<I 

 with its blue-purple corollas. It was stated to 

 the writer that artists freijuently endeavour to 

 reproduce on canvas the colour eft'ects exhibited 

 by these flowers. Associateil with them were 

 the more sober tinted plants of the goose- 

 foot tribe. Amongst these may be specified 

 AtripU.x lilloralis L., A. porlulacoides L., the 

 marsh samphires Salicornia herhacea L. , also S. 

 nitiiians Sm., and Siiaeda marilima Dumorlt. Our 

 visit was just at the time when it is customary to 

 gather marsh samphire, or"sampher" of the natives, 

 lor culinary purposes. It was noticed that they were 

 careful in their selection of the plants for this purpose. 

 So far as one could see -V. radUans wxi avoided, and it 

 was locally called "sheep's sampher." To search 

 these mud flats effectually, it is expedient to adopt 

 the local method of traversing them, that is with 

 bare feet. Attending this method is the great 

 advantage of having dry foot-gear to don when leaving 

 the marshes, the benefit of which is obvious. 



( >n the waste ground to the east of the head of 

 Wells Harbour, the most conspicuous plants were : 



Beta maritifita L. , tlic very local Siiaeda friilicosa 

 I'orsk., and the curious grass Lepliinu ftliformis Trin. 

 The last mentioned Ls so inconspicuous that the sjKit 

 was passed over severa 1 times before it was observed. 

 The salt water ditches near were crowded with 

 Sdrpiis marilimtis L. In the fresh-water dykes 

 between llolkham aiid Wells there were noticed the 

 usual plants of such situations. One need only men- 

 tion IKUamogclon polys;oiiifoliiis Pourr. , Elodia 

 canadensis .Mich.x. , A'loncw hydrolapalhiitn Iluds., 

 Sparganiiiin ramosum Iluds., and S. simplex Muds. 



Near Warham, about two miles east from \\ 1 1 

 and not far from the excellently preser\-ed Danish 

 C.imp, there flourished in a broad ditch the white 

 water lily, and homwort in fine fruit. Near the 

 eastern end of the Wells golf links, the curio 

 umbellifer, Bupleurtim tenuissimuin L. , occurs 

 small ((uantity by a little pool. Both this and its near 

 ally B. rotiindifolinm L. have the perplexing habit of 

 simulating £K//iwi/a in their inflorescence. Probably 

 surt'icient has been written in the foregoing brief 

 account to show that the neighbourhood of Wells- 

 nexl-the-Sea will well repay the efforts of an 

 enthusiastic plant lover. 



41}, Kol/tesay Rood, Luton. 



RAUIOGR.MMl.V 

 By James Quick. 



{Continued /rotn page 136.) 



A A 'E must now discuss more in detail the working 

 '' parts of an X-Ray outfit. The four chief items 

 comprising this are, (a) the induction coil, (/') the 

 battery, (r) the X-Ray tube, and (rf) the fluorescent 

 screen. The size 

 of an outfit is gen- 

 erally associated 

 with the length of 

 spark given by the 

 induction coil. A 

 12 -inch set, for 

 instance, includes 

 a coil giving a 12- 

 inch spark, and so 

 forth. Fig. 4 de- 

 picts a 4-inch set 

 and shows the 

 connections of the 

 battery with the 

 terminals of the 

 primary coil of 



the induction coil, also those of the X-Ray tube with 

 the secondary coil. The tube is shown arranged in 

 a clip, for taking a radiograph of the object on the 

 table. 



This is a small set, and now very seldom used in 

 hospital practice. The usual size for that purpose 

 being a 10 to 16-inch. Coil^ giving "P 'o 24-inch 

 spark length, are sometimes used for special work. 



Fig. 4. — .\PPARATL S ARRANGED FOR TAKING A RapIOGRAPH 



Taking now each item separately and beginning 

 with the induction coil, it will, perhaps, be useful 

 to say a few words first upon its working principles and 

 its construction. Suppose two coils,A and B, such as 



are shown in fig. 5, 

 are taken, and the 

 terminals of B con - 

 nected to a gal- 

 vanometer ; if a 

 current of elec- 

 tricity is sent 

 through A, a mo- 

 mentary current 

 will be induced 

 in B, which will 

 deflect the needle 

 of the galvano- 

 meter. A is called 

 the primary and B 

 the secondary coil. 

 Should thecurrent 

 in A be now stopped, a current will again be 

 induced in -B, but in the opposite direction, and 

 the deflection of the needle will be the reverse 

 of that in the first instance. If the circuit of 

 A is made and broken quickly, there will 

 be corresponding alternating currents momentarily 

 induced in B, the smaller the time taken to actually 

 make and break the circuit, the higher will be the 



