>3 6 



SCIENCE- GOSSIP. 



strangers prefer rain-water collected in a cistern, 

 and sold for five farthings a gugglet. It was a 

 favourite amusement with me to watch them whilst 

 they drank the holy water, and to taunt their scant 

 and irreverent potations." 



It is interesting to compare with this account 

 the results of the analysis made by the writer. 

 On opening the bottles, which were hermetically 

 soldered, they were found to be filled with water 

 in which were suspended beautiful silken crystals. 

 which proved to be a compound of tin, evidently 

 derived from the action of the water upon the 

 interior of the vessel. On filtering the water a 

 clear and colourless nitrate was obtained, whilst 

 the crystals and some earthy matter were left on 

 the filter. The water had a slight odour, which 

 was more perceptible on gently warming. 



The amount of solid matter left on evaporation 

 was in the proportion of 219-5 grains per gallon. 

 If this be compared with Thames water, which 

 contains about 29 grains per gallon, or with Xew 

 River water, with 25 grains, some idea will be 

 obtained of the large proportion of salts which 

 this figure represents. It was typical of a strongly 

 saline mineral water. 



The chlorine, largely present in the form of 

 common salt, was 69 - 3 grains per gallon, with 

 which again compare Thames water with l - 4 grain 

 and New River water with 1-8 grain. A large 

 proportion of this chlorine was probably derived^ 

 from the soil ; but at the same time it is not going 

 too far to attribute some of it to the pilgrims, 

 seeing that salt is excreted by the human skin. A 

 water containing as much as 9 grains of chlorine 

 per gallon is looked upon with suspicion, unless it 

 is satisfactorily accounted for by the known nature 

 of the bearing strata. 



The quantity of magnesium, which was probably 

 all present in the form of magnesium sulphate or 

 Epsom salts, was not so large as might have been 

 expected from the descriptions which have been 

 given of the taste of the water. It amounted to 

 6 - 6 grains per gallon. The degree of hardness was 

 determined by the well-known Clarke's test. In 

 this the w T ater is shaken with a solution of soap of 

 known strength, which is added in gradually in- 

 creasing quantities until a permanent lather is 

 obtained. This does not happen until the whole of 

 the carbonate of lime or its equivalent in other 

 salts has been neutralised by the soap. The 

 amount of soap solution used is expressed in terms 

 of carbonate of lime, each degree corresponding to 

 1 grain per gallon. The hardness of the Zem-zem 

 water was 43°, as against 17° for Thames water and 

 15° for Xew River water. Hence it will be seen 

 that it was excessively hard. 



A very important test for judging the character 

 of a water is the determination of the amount of 

 " free " and organically combined ammonia. A 

 large proportion of the ammonium was present in the 

 form of salts, probably combined with part of the 



chlorine, as ammonium chloride or sal-ammoniac. 

 The combined organic ammonia amounted to 22 

 parts per million. A good drinking water does not 

 contain as much as 0-1 part per million of such 

 ammonia, and the high proportion found here is 

 what one would expect in a highly contaminated 

 water. The amount of nitrates was also indicative 

 of pollution. 



The following table gives the quantity of the 

 chief constituents of the water : — 



Per cent. Per cent. 



Aluminium 0-8 Potassium .. 24-3 



Calcium 0-5 Ammonium .. 5-3 



Silica 3-U Chlorine . . . . 69-3 



Magnesium 0-6 Sulphates .. 30'7 



Sodium 38-3 Nitrates.. .. 19-9 



It is interesting to note that on bacteriological 

 examination the water was found to be absolutely 

 sterile, though this is not surprising when we re- 

 member that it had been sealed up in an air-tight 

 vessel and in total darkness for over forty years. 



I have to thank Mr. Frank Percy Smith for 

 having kindly made the excellent drawing from 

 the original tin flask, illustrating this article. 



57 Chancery Lane, London, March 1901. 



BUTTERFLIES OF THE PALAE- 



ARCTIC KEG-IOX. 



By Henry Charles Lang, M.D., M.R.C.S., 

 L.R.C.P. Loxd., F.E.S. 



(Continued from p. 300.) 

 Genus COLLAS (continued'). 



In the second section of Group I., about to be 

 described, we have several species that are quite 

 as brightly coloured as those of the first section ; 

 and, as in the case of Colias regia and C. eogene, 

 some that reach the maximum of intensity in the 

 coloration of the genus. They are all charac- 

 terised, however, by the absence of the basal patch 

 on the h.w. of the $ . 



10. C. romanovi Gr.-Gr. Rom. Mem. vol. 

 iv.. 1890. 



46 — 50 mm. 



$ deep orange, with borders very much as in 

 Colias aurora, but the nervures are not black. 

 The border of the f.w. is not sharply defined at its 

 inner edge, but shaded or streaked. It has a few 

 yellow rays near the apex ; there are also very 

 frequently to be seen upon it some traces of yellow 

 spots. In spite of this last character C. romanovi 

 must come into this group ; first, because the 

 spotted border in the male does not seem to be 

 the normal condition of the species, though four 

 out of five males in my collection possess it. 

 Indeed, the name maadata is sometimes given to 

 this form. Secondly, because of its proximity to 

 C. aurora and the allied species. Gr.-Gr. says of 



