Scientific Proceedings. 



(247) 77 



bron were the same : 



C 41 H 79 N0 8 + 2H,0 = C ]8 H 36 0 2 + C n H a5 N0 2 + C 6 H 12 0 6 



Phrenosin Neurostearic Sphingosin Galactose 



acid 



C 49 H 9 ,N0 9 + 2H 2 0 C^H^ + C 17 H 35 N0 2 + C 6 H 12 0 



Cerebron Cerebronic Sphingosin Galactose 



acid 



50 (142). "A simple electrical annunciator for use in metabo- 

 lism experiments, and in connection with filtration, distilla- 

 tion and similar operations," with demonstrations : WILLIAM 

 H. WELKER. (Communicated by WILLIAM J. GlES.) 



In the paper describing his cage for metabolism experiments 

 the writer 1 referred to the advantages of the " sliding shelf" devised 

 as a holder for the urine receiver, and, in that connection, made the 

 following remark : " The shelf also favors the use of electrical 

 apparatus to ring out the time of elimination of urine-fractions, in 

 experiments in which fractions of the urine must be examined sepa- 

 rately and immediately after their natural excretion " (page 407). 

 This remark alludes to one of the several additional devices the 

 writer had intended to perfect for use with the cage described. 



In order that an annunciater might be of the greatest service in 

 metabolism work in the way already indicated, and also to insure its 

 usefulness for filtration, distillation and other operations in which the 

 weight of a product above a certain maximum amount could be 

 relied upon to close an electrical circuit and announce the delivery 

 of the material, it was necessary that it should be delicately respon- 

 sive to the weight of several grams and yet be readily adjustable 

 within relatively wide limits in that respect ; that it should be light 

 in weight, of small compass but durable, and resistant to derange- 

 ment from any cause ; also that it should hold, without risk of loss 

 or modification of the contents, any suitable vessel placed upon it. 



At the writer's request, Mr. Welker, who has exhibited in this 

 laboratory unusual proficiency in handling electrical apparatus, de- 

 vised an annunciator to meet these requirements and has perfected 

 an apparatus that is eminently satisfactory for all the purposes 

 contemplated. 



The annunciator shown to the Society consists of two square 

 boards (4^ x 4^ x y% inch) securely fastened together with a 

 piano hinge on one side, and kept apart, by a spring perpendicularly 



1 Gies : American Journal of Physiology, 1905, xiv, p. 403. 



