ABSTHACTS OF RITOHTS OF FOIIFIIIN INVFSTIIIATION.l 



The grading of bone meal. J. Konig (Latuhr. Zff/. f. West/nlcn it. 

 Lii>j>r, l.s!)/, pp. :'i,'). \'iiii). — rinlcssor Jvoiiig" desififnjitcs as " iionnal" 

 lliat hone meal which has hccu freed of its fjit by chi'inical means 

 (dissolviiii^- in hcnzinc, caihon liisnlphide, etc.), leaA'inj^' tlio "^'chitin 

 iinat lacked. It thus contains from 4..") to 5,2 per cent of nitroj^en, and 

 from 1 !).."> to 23 per cent of i)hosphoric acid. He states that it is a 

 «'ommon ]>ractico amon^- mannfactnrcrs in Clcrmany to mix witli the 

 ]>nn' meal pre[)ared in tliis way meal from Miiich tlie jiclatinous mate- 

 rials have been extracted l)y treatinji' with superheated steam, thus 

 fnrnisliino' a mixture whicli has a somewliat smaller ]»ercenta,!ie of 

 nilrojicn and a larger [>er<'enta^'e of phos[»horic acid than the so-caHed 

 normal meal. The jx'rceutaji^e of nitrogen is further dependent on the 

 amount of meat, horn, etc., Avhich is mixed with the bones and which 

 he ])ronounces of less manurial value than the gelatinous materials of 

 the bones. These other uitrogenous materials can be quantitatively 

 sei)arated from the bones, he says, by shaking with chloroform ; being 

 lighter than tlie bone they rise to the surface. Normal bone meal may 

 contain IVom 1 to 5 i)er cent of siu'h materials, hut not more than this 

 amount should be i)resent. He suggests that the quality of the bone meal 

 may be safely graded on the basis of the relation of the phosphoric acid 

 to the nitrogen remaining after extraction with chlorolorm. and he pro- 

 ])oses the following classilicatiou: 



(1) Bone meal containing 4-5.,3 per cent nitrogen and JI>.r)-2;> per 

 cent ])hosphoric acid, and in wliich after treatment with chloroform the 

 nitrogen and pliosphoric aci<l are in tlu' pro])ortion of 1 : 4-.").;"), is to be 

 designated as nonnaJ hone meal, or hone meal N^o. 0. 



(2) Bone meal containing 3-4 per cent nitrogen and 21-2.") ])er cent 

 l)hosphoric acid, and in which after treatment with chloroform the 

 l)roi)ortion of nitrogen to phosphoric acid is as 1: r)..~)-8.r», he designates 

 simjdy as hone meal. 



(.3) Bone meal containing 1-3 per cent of nitrogen and 24-30 per cent 

 of phos[)horic acid, tlie proportion after treatment with chloroform 

 being as 1:8.5-450, he designat<\s as dcgelatinized hone meal. 



(4) Only such meal is designated as rair as has been prepared by 

 pulverizing raw untreated bones. 



(5) Meal which after treatment witli chloroform contains less than 1 



per cent of nitrogen derived from the bone gelatin, and in which the 



relation of nitrogen to phosphoric a<'id is wider than 1:30, is not to be 



classed as a bone meal, but designated as mixed fertilizer meal. 



165 



