192 CORRESPONDENCE. 



however reasonable they may seem. If I were to try, it would take 

 me immense labour to write a long letter to each of twenty persons, 

 perhaps, which ten out of twenty would not understand, and would 

 not reply to ; and the few who might comply would be almost sure to 

 send something not pleasing to you. If you go one inch out of the 

 daily beaten track every obstacle is thrown in the way, and everything 

 that is possible is done wrong. If I could get you twenty dips the 

 time alone would be worth 20s. " With thanks, I am, &c." 



Now, I should think something might be done to make these 

 vendors more reasonable, who thus attempt to force amateurs who 

 want to make a systematic collection of selected slides, to purchase 

 only their selections, at from eighteenpence upwards; or if they 

 cannot be brought to reason, we have the remedy in our own hands if 

 we choose to apjily it. In London, or in such a town as Liverpool, 

 where ships are daily coming in from all parts of the world, I am sure 

 it would pay an optician, as a business speculation, to order a quantity 

 of diatomaceous deposits and foraminiferous sands, &c., &c. The 

 localities where they are to be obtained are perfectly well known ; the 

 price of the raw material in those places is little more than the cost 

 of labour in collecting them. The freight of a few hundredweights 

 would be trifling, and they could be sold, either prepared or unpre- 

 pared, at two or three hundred per cent, profit, and if properly adver- 

 tised, and if notification of the fact of their being on sale were sent to 

 all the Secretaries of Microscopical Societies in England, I venture 

 to say the deposits would not remain long on hand. 



It may be said that it is difficult, if not impossible, to find out 

 what towns possess Microscopical Societies. I think this difficulty 

 might be met by proposing that any provincial association might be 

 affiliated to the Eoyal Microscopical Society by paying a yearly fee 

 of, say, half-a-crown to have its title and the names of its President 

 and Secretary registered ; and if lists of such societies were periodi- 

 cally issued, sufficient publicity would be obtained. 



With regard to British species, nothing could be easier than to 

 facilitate their dissemination by the following plan. It is astonishing 

 what a very small quantity from any gathering is amply sufficient for 

 a man's own use. Suppose that every member of a Microscopical 

 Society who made a gathering or preparation, whether marine or 

 fresh-water, after carefully examining it, and noting the particular 

 diatoms it contained, should present what he did not require for his 

 own use to the society to which he belonged, of all of which prejiara- 

 tions the Secretary should make a list. Now, although the individual 

 might not like to sell his preparation, I can see no reason why the 

 society might not sell it, at so much a dip, according to its plentifulness 

 or scarcity, and the trouble and expense of cleaning it ; but I should 

 think from 2(Z. to 6d. a dip would be ample, and a common medium for 

 advertising these could easily be found. Such a mode of proceeding 

 would, of course, not interfere with gentlemen exchanging their 

 mounted slides as they do at present. 



Can you or any of your readers suggest a better mode of obtaining 

 material, by which so many more of us might be able to profit by 



