268 



Scientific Intelligence. 



the jet extends into the combustion tube sometimes cracking it, and oth- 

 erwise, without this issue, causing the loss of the whole determination. 

 This catastrophe is especially to be feared toward the conclusion of 

 the combustion, when little ex 

 of the tube. 



or tartaric acid with the body" to be analyzed, that other gases in quan 

 tity might be furnished and the ammonia thus diluted. The difficulty to 

 some extent still remained, and gave rise to Schlossberger's apparatus. 



pt pure ammonia occupies the interior 

 MM. Varrentrap and Will suggested the mixture of sugar 



Fig. 1.— Varrentrapp and Will's Apparatus. 



Fig. 2. — Schlo'ssberger's Apparatus. 



ih ^ — * ■*- 



It consisted of two little flasks, of the size used in alkalimetry by 

 esenius and Will. rnnnvnt&A 1™ *.ih A or>rl ™-i™ ««ri -» ^;o™c*>rl n« to 



admit air from without, in the event of condensation, without the pos- 

 sibility of the acid ascending into the combustion tube. This improve- 

 ment most effectually removed all liability to danger. 



It had however two objections :— complication and cork surfaces. It 



18 ?,?, ( ! se(i of seven Pieces, while the apparatus of MM. Varrentrap 

 and Will consists of but one. 



To unite the safety of the former with the simplicity of the latter, 

 was a great desideratum. 



An examination of the conditions of the problem, renders its solu- 

 tion easy. r 



The starting back of the acid follows an absorption more rapid than 

 the evolution. The fluid that had been driven forward into the second 

 and tf J"rd bulbs, slowly returns toward the first. As the acid enters 

 the bulb nearest the combustion tubes, the sudden expansion of its sur- 

 tace occasions such rapid absorption that a partial vacuum is produced. 

 Ihe liquid comes in so fast, that with the rush of air and vapor into the 

 condensation tube, some of the acid is carried with it. 



Ihe causes of the difficulty are the too rapid increase of absorbing 

 surface, and the smallness of the bulb. These are removed in the 



Kg- 3. — Improvement upon Fig. 1 



slight modification of the apparatus re K 

 realized all the expectations entertained. 



3. Its use 



has 



Laborat 



It is entirely safe. 



