SCIENCE-GOSSIP. 



203 



These crystals are exceedingly corroded, both 

 along the edges and at numerous small patches in 

 the interior, and they evidently represent crystals 

 which have been " erupted " along with the other 

 volcanic matter which forms the rock, and by 

 floating about in the molten magma have suffered 

 this corrosion and abrasion. One or two of these 

 crystals are seen to be bent in various ways, one 

 comparatively long one being bent bow-shaped. 



I think this bending must have taken place before 

 the consolidation of the rock, as the crystals 

 merely lie in the fine base mentioned, and are not 

 in contact with any other crystals. The first- 

 mentioned felspars contain numerous inclusions 

 of an acicular nature. The microscopic evidence 

 shows this pebble to belong to the Pyroclastic 

 rocks. 



{To be continued.) 



SERIAL POPULAR SCIENTIFIC LITERATURE. 



'"PHERE are now and again offered to the public 

 works of a semi-scientific nature, to be issued 

 in serial numbers, which, although they may not 

 in the end belie the promises held out in the 

 prospectns, are yet, from their often attractive 

 appearance, liable to mislead young people — and 

 older ones too — into an expenditure which is 

 afterwards regretted. The prospectus of such a 

 publication is probably as complete as can be 

 expected from a purely business point of view, in 

 that it states what the book is, but as we are not 

 informed what the book is not, wrong inferences as 

 to its character are inadvertently drawn, ultimately 

 resulting in grave disappointment. 



To make the case clear, let me give an example : 

 Some time ago, I took in, in monthly parts, a work 

 on a natural history subject, thinking it would be 

 useful to my children. It ran to four volumes, and 

 cost altogether, including binding, over two pounds 

 ten shillings. No definite order was observed in 

 the arrangement, and the comparison of allied 

 species placed here or there, in one or other of the 

 volumes indiscriminately, involved such incon- 

 venience as to render the work practically almost 

 useless. 



The " Classified Index " was an afterthought, 



added at an extra charge, and would have been of 



some value had it been interspersed with the bare 



names of the excluded but often common species 



in their proper places, say in different type. The 



character of the " General Index " may be judged 



from what follows. Supposing the work, which I 



I specify, to have been on Botany, none of 



the buttercups would occur under B, but one 



would be ur.'ier C . thus, creeping buttercup; and 



another !.', as "upright meadow buttercup." Or 



supposing this subject to have been liirds. and 



none of the owls under O, nor the wagtails under W. 



If not a fancy picture— qniti iry. 



\ the vo 1 ranged the 



items according to the classified index, added the 



excluded species in MS. on blank leaves inserted 



for the purpose, and copied from a useful little 



hich cost a •billing, and rcpag- 



The work embraced descriptions and G 



of about forty per cent of the British l| 



which, to be impartial, was as much as was to be 

 expected from the prospectus if carefully read, by 

 an experienced person. But mark the italics. Some 

 of the figures were irremediably mixed, and this 

 gave a great amount of trouble. The re-binding 

 in the new form raised the cost to nearly three 

 pounds in cash, to which is to be added the value 

 of the labour of re-indexing, etc. The whole 

 furnishes an example of how a too trustful public 

 may be led by the " serial " system to waste sums 

 of money on imperfect productions, which money 

 otherwise expended would procure works of 

 scientific value. It may be added that some 

 common objects were omitted altogether. 



Well may one ask, what would an admirer of 

 field-flowers seeking information about, say, a 

 buttercup with the sepals always reflexed, feel but 

 disgust on taking down a fifty-shilling book and 

 finding no reference whatever to the plant ? This 

 may not be the best illustration that can be given, 

 but it will serve its purpose. 



My advice to young people interested in any 

 scientific subject is, when you see a serial publica- 

 tion advertised, put the monthly or weekly amount 

 it will cost away in a box until you can get that, or 

 possibly some better work, entire. In the mean- 

 time borrow from friends, or go to a public library, 

 or obtain by any other possible means the 

 information you need. 



My remarks do not apply to really scientific 

 works produced in parts, each one complete in 

 itself. By taking such one becomes posted up-to- 

 date in that portion of the subject treated. Pub- 

 lishers of the kind of literature here condemned 

 may possibly urge that it creates a thirst for 

 knowledge. Very well, but the game is not worth 

 the candle when, as in the case in point, that same 

 iay be created by such comprehensive little 

 1 Eggs," or Bagnall's or fry's 



i.-s," which will form safe guides and cost a 

 shilling each. At half-a-crown to five hillings 

 there are books to be had on almost any branch of 

 of natural science, which are at the same time 

 interesting, inairn fairly comprehensive 



W, 11 in ro . 



tbury. 



