THE AGRICULTURAL JOURNAL. 



445 



Sibsoa's work, which !I am unfortunately 

 unacquainted with, it clearly means that 

 commercial muriate contains 80 per cent, 

 of pure muriate, the other 20 per cent, 

 being impurities. This is nowadays a 

 very low standard indeed ; a first-class 

 sample would be 98 per cent. pure. It is 

 a chemical impossibility for muriate to 

 contain 80 per cent, of potash. 



As to Mr. Thorrold's diliiculties with 

 regard to the formulae for fertilisers, I 

 confess that I cannot quite follow his 

 calculations, especially the method by 

 which he has arrived at 20 lbs. of muriatp 

 of potash in formula No. 3. I fancy he 

 has understood the percentages given in 

 formula No. 2 to mean so many pounds 

 per acre, which is quite a mistake. The 

 percentages mean that every 100 lbs. of 

 the mixed manure should contain 4 lbs. 

 nitrogen, 7 lbs. phosphoric acid, and 4 to 

 9 lbs. of potash. If we take his figures 

 (making an alteration in accordance with 

 the explanation given above we find that 

 to provide 4 lbs. potash will require 'if, or 

 say 7 lbs. of the muriate) the formula 

 works out thus :— 



Nitrate of soda 27 lbs. 



Dissolved bones .. ... .56 „ 



Mui-iate of potash ... 7 „ 



Total 90 „ 



This only totals up to 90 lbs, so he 

 must either use 90 lbs. instead of every 

 100 lbs. recommended, or add 10 lbs. of 

 dry earth or similar substance to make up 

 the full 100 lbs., which will then contain 

 the proper percentage. But this has 

 nothing whatever to do with the amount 

 applied per acre ; in fact, he must use 

 about six times as much per acre to come 

 near to the amounts proposed in his 

 formula No. 1 ; the weights being then : 



Nitrate of soda ... 1()2 lbs. per acre 

 Dissolved bones 336 „ „ 

 Muriate of potash .. 42 „ „ 



Equal to 600 lbs. of manure made to the 

 standard of formula No. 2. I might 

 suggest that it would be unwis:' to mix 

 the manure as suggested, as the nitrate 

 would be acted upon by the acid in the 

 dissolved bones, and the nitrogen wasted. 

 He should either use sulphate of am- 



monia instead of the nitrate, or apply the 

 latter as a top dressing after the crop is 

 up. 



Yours &c.. 



Arch. Pearce. 



Sir, — Regarding Mr. James Thorrold's 

 letter in the last Journal, in a measure re- 

 ferring to Mr. Archibald Pearce's article of 

 the pi'evious issue entitled " Agricultural 

 Analysis," I am glad the subject has 

 come under discussion, as I am of 

 opinion that too much light cannot 

 be thrown on the question of arti- 

 ficial manures at the disposal of our 

 farmers ; and am glad to learn there is a 

 desire to have a little more publicity as 

 to their sources and composition, so that 

 they may be tabulated, as far as possible, 

 in such a form that intending purchasers 

 may with some confidence select those 

 which will suit their purpose. The 

 matter is of sufficient vital interest to 

 agriculturists to warrant the undertaking, 

 and merchants dealing in artificials should 

 have nothing to fear from such an ex- 

 posure, in most cases, as it will advertise 

 their wares for what they are worth, and 

 give them a standing which will speak 

 for itself. It is, however, only fair that the 

 merchants should either voluntarily submit 

 samples for analysis, or, that they should 

 receive due notice from the purchaser 

 after dispatch of the manures, that it is 

 the intention to submit samples for 

 analysis and publication. 



Mr. Thorrold's dilemma is certainly 

 that of many others, and it is well that 

 such difficulties should be expressed and 

 discussed for their own edification and 

 that of others. In Mr. Thorrold's en- 

 deavour to point out his difficulties, he 

 assuredly does not simplify the matter of 

 explanation, as his reasoning has led him 

 into rather intricate paths. In the case 

 of kainit, Mr. Pearce states it rightly 

 when he says that this article contains 

 about 13 per cent, of potash and the 

 muriate or chloride about 60 per cent, or 

 the equivalent of 60 per cent. The mis- 

 understanding seems to arise from a mis- 

 interpretation of the note in Messrs. 

 Henwood & Company's handbook, where 

 I believe it states that kainit contains 

 nearly 25 per cent, of sulphate of potash. 

 If that is so, then be it noted, that it is 

 25 per cent, of the sulphate, not of potash ; 



