APPENDIX B. 



« • 



xvn 



'^^% the 



c 



% 



> ^Pof 



be brou 



■e birth to 

 oxalate are 



ght 



\ 



^ent, and cark 



-crjstjl- 



lOf 



non 



x'sts in the foa 

 >vas within 

 Dund. 



; particularly, it 



< » 



•igin or mode ol 

 :ic acid enteriB? 



the crude 



7 



id althous 



living 



■r to obtain tie 



I most certainlf 

 might have con- 



irtrate has 

 precipitated b)' 



The ins 

 •al time^- is 



cid, 

 this 



r before 



mixtuf^ 



li 



a 





ute 



gulp 





can be obtained from which the first crystals of tartaric acid 

 are procurable. Ammonia, the other constituent of the 

 neutral tartrate, being a product of the destructive distillation 

 of coal tar— and itself exercising such a destructive influence 

 upon organic matter when existing in the form of strong 

 liquor ammomcp — would not seem to be a very promising 

 nidus for living ' germs/ The neutral tartrate of ammonia 

 is, however, prepared by mixing a solution of tartaric acid, 

 procured as above mentioned, with an adequate quantity of 

 liquor ammonise, and then evaporating the mixture at a 

 gentle heat. Thus prepared, the crystals contain a notable 

 quantity of water of crystallization. 



In the stock of crystals procured from Messrs, Hopkin 

 and Williams\ which had been made about six months pre- 

 viously, some were well formed, and almost perfectly trans- 

 parent, whilst others were less regular in shape, and pre- 

 sented an opaque appearance with more or less of striation 

 within. When a crystal of moderate size was taken, about 

 ^' in diameter, or a portion of a larger one, and placed in 

 a large watch-glass with some distilled water, it was frequently 

 found that at first a certain number of opaque-white 

 scales, having a granular aspect under a high magnifying 

 power, dropped from the surface of the crystal to the bottom 

 of the watch-glass. This material, which seemed to have been 

 produced by some superficial alteration (efflorescence) of the 

 substance of the salt, dissolved with much more difliculty 

 than the unaltered matter of the crystal It remained for a 

 long time at the bottom of the glass, and only very slowly 

 disappeared. As the substance of the crystal thus dis- 

 solved away, a number of large and small gaseous bubbles 

 gradually escaped from it. When the crystal was examined 



r 



^^ordi7iary temperatures, has been found to be peculiarly destructive to 



ainiving things. 



^ Of New Cavendish Street. 



VOL. 11. • 



