THE ALBUMINS. 289 



employed when there is reason to believe that albumoses are present 

 only in traces. The collected twenty-four hoars' urine is carefully 

 neutralized, concentrated to about 1000 c.c. at 60-70 C., filtered, 

 and saturated with ammonium sulphate in substance. The pre- 

 cipitate is collected on a filter, and dissolved in a little water, when 

 a small portion is treated with an equal volume of a saturated solu- 

 tion of common salt, and with acetic acid or nitric acid drop by 

 drop so long as any precipitate that has formed is thus increased. 

 The solution is then boiled. If coagulable albumins are present, 

 these are precipitated, and are filtered off from the hot solution. If 

 the filtrate becomes turbid again on cooling, and clears upon sub- 

 sequent boiling, the presence of albumoses may be inferred. To 

 determine the character of the albumoses in question, the remaining 

 liquid is dialyzed (see above), freed from nucleo-albumin by means 

 of acetic acid, neutralize:!, concentrated on a water-bath, and 

 saturated with rock-salt. If primary albumoses are present, they 

 are thus precipitated and filtered off. When acetic acid that has 

 been saturated with common salt is added to the filtrate the deutero- 

 albumoses are thrown down. This test should be applied in the 

 preliminary examination also if no reaction is obtained. 



Instead of using sodium chloride to precipitate the albumoses, 

 ammonium sulphate can, of course, also be used, as has been 

 described on page 184. 



True peptones, in the sense of Kuhne, do not occur in the 

 urine, and it is hence unnecessary to describe the older and more 

 complicated methods which formerly were employed in their search. 



Bence Jones' Albumin. -This body, as has been pointed out, has 

 repeatedly been encountered in the urine in association with the 

 existence of multiple myelomata of the bones. Of its nature, 

 however, little is known. Most observers have regarded it as an 

 albumose, but it is admitted that it is not identical with any of the 

 known digestive albumoses. Like the globulin described by Paton, 

 it has been found in crystalline form in the urinary sediment. 

 Magnus-Levy, who has recently studied the body in question, while 

 likewise unable to identify it with any of the known albumins or 

 albumoses, points out that it has in reality only one property in 

 common with the albumoses, viz., the solubility of its precipitate on 

 boiling. He points out, however, that this is only apparent, and 

 that under suitable conditions the body is coagulated on heating to 

 100 C., like the native albumins. He further noted that, like the 

 true albumins, the substance yields the common digestive products 

 of these bodies, viz., primary and secondary albumoses ; but, as in 

 the case of casein, no hetero-group could be demonstrated. These 

 results I have personally confirmed, and it is thus conclusively 

 established that the body cannot be an albumose. Pending further 

 investigations, it is hence advisable to term the substance the 

 albumin of Bence Jones. Of its origin nothing definite is known. 

 The amount which is often found, however, is so large that the con- 



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