172 TALKS ON MAN IRKS. 



These were the rcsuHs of llie harvL-st of 1844. The first year of 

 these since cek'bratod exponiiients. 



If Mr. Lawes e.xpected that the crops would be iu proportion to 

 the minerals supplied in the uiauure, he must have been greatly 

 disappointed. The plot without mauure of any kind, gave 15 

 fnishels of wheat per acre; 700 lbs. of superphosphate of lime, 

 made from burnt bones, produced only ii'6 lbs. or about half a 

 bushel more grain per acre, and 4 lbs. ksi straw than was obtained 

 witliout manure. UIO lbs. of superphosphate, and G5 lbs. of com- 

 m^Tcial sul|)hate of ainmonia (erju il to about li lbs. of ammonia), 

 give a little over l!)i Inishels of dressed wheat j^r acre. As com- 

 pared with the plot having 700 lbs. of superphi>spl.at<' per acre, this 

 14 lbs. of available ammonia per acre, or, say lU lbs. nitrogen, 

 gave an increase of 824 lbs. of grain, and 2o2 lits. of straw, or a 

 total increase of 570 lbs. of grain and straw. 



On plot No. I'J, 81 lbs. of sulphate ammonia, with minerals, pro- 

 duces 24i bushels per acre. This yield Is clearly due to the am- 

 n)onia. 



The rape-cake contains about 5 per cent of nitrogen, and is also 

 ridi in minerals and r iroomi^oiin mutUr. It gives an increase, but 

 not as large in proportion to tlie nitrogen furnislied, as the sul- 

 piiate of ammonia. And the same remarks apply to the 14 tons 

 of farm-yard manure. 



We slioidd liave expected a greater incroa.sp from such a liberal 

 dre.s.sing of barn-yard manure. I think the explanation is this: 



transparont claps, sliphtly deliqnc«C(;nt in the air. which was gronDd to a pow- 



<llT UIlliiT OajJl-Ht'lDi'ti. 



^ The nianuri's tfrnifd piiporpliocphato nf limo. phospliat'' of pnt;»8fi. phocphate 

 (if !<i>d:i, mill ptu>>pli:it<' of mairm-ciii. wrrr niado hy acting iipnn hmic-iish l>y 

 nii'Hiis (if >iilpliurii' acid in thr fir-»t iiictanri-. and in the ca»""- <if lln' alkiili salts 

 and till' nmirni'sian one ncntralizini: thi- rointxiiind thus olitaincd by moatis of 

 Ciii-ap preparations of the re-pectivc liases. For the snperpliopplmte of linio, 

 the propdrtions were ."> parts hone-asli. 3 part? water, and ■\ parts siilplinrie acid 

 of .sp. L,'r. I>1; and for the plidsphates iif potas!". soda, and niafnesia. they 

 were 1 parts hone-ash. water as needed. :\ p.art- sill phurie acid of sp. pr, l.si. and 

 et|iiivah-iit amounts, respectively, of pearl-ash. soda-ash, or a mixture of 1 

 part medicinal carbonate of majrnesia, and I narts mai,'n<'sian lim<-stone. 'l"he 

 mixtures, of course, all lost weight considcraoly by the evolution of water and 

 carbonic acid. 



* .Made with nnbnmt bones. 



' In this first season, neither the weiijhl nor the measure of the offal rorn was 

 recorded separately ; and in former papi-rs, the busluds and jiecks of total corn 

 (including; otrah have erroneously been given as dressed corn. To brine the 

 records more in conformity with those relating to the other years 5 per cent, 

 by weiirhl, has been deducted from the total corn previou-ly stati-d as dressed 

 corn, and is recorde<i as offal corn ; this being about the probable protiortion. 

 judging from the character of the season, the bulk of the crop, and the weight 

 per bushel of the dressed corn .Mthough not strictly correct, the statements of 

 dresM'd corn, as amended in this somewhat arbitrarv way. will ap|iroximatc 

 more nearly to the truth, atid be more ciimparable with those relating to other 

 BeaBon.s, than those hitherto recorded. 



