480 TRANSACTIONS OP THE AMERICAN INSTITUTE. 



peratuve Is a glass tube bent in the form of a semi-cii-cle, one extremity being 

 closed and attached to the circumference of a metallic wheel resting on knife 

 edges and counterpoised. A mercurial index is attached to the glass tube, 

 which divides it into two chambers, one closed, the other open to the air. The 

 metallic tube is passed through the mercury into the closed chamber of the 

 glass tube. On the axis of the wheel is an arm carrying a tracing point 

 which marks the variations on the registering cylinder. When the bulb is 

 heated the air passes into the closed portion of the glass tube, forces back the 

 mercury, and of course disturbs the equilibrium of the apparatus to an extent 

 marked by the tracing point on the cylinder. The metal air tube is furnished 

 with a valve near the bulb, so that the interior may be placed in communica- 

 tion with the exterior, in order to set the apparatus to zero. 



Influence of Odor on Silkworms. 



• 



M. E. Fairre read a paper before the French Academy, in which it appears 

 that, although the silkworms are inconvenienced and many are destroyed in 

 consequt nee of the presence of certain aromatic leaves beneath their ordinary 

 food, those which survive arc impelled to spin up sooner, and to produce finer 

 cocoons than those which have not been subjected to this exceptional 

 treatment. 



Gas in Egypt. 



The city of Alexandria was lighted by gas for the first time on the 23d of 

 December last. The lamplighter is nightly followed in his rounds by a crowd 

 of wandering Arabs, who insist that the marvellous blaze following his touch 

 must be provoked by the will of genii. The improvement has made great 

 changes in the habits of the place. The municipal order requiring everybody 

 going abroad after dark to carry his own lantern has been rescinded. 



HlPPOPSAGOUS. 



The brilliant Paris correspondent of the New York Tribune gives, in the 

 following, some interesting statistics relating to animal food : 



Economical bucolic readers of The Tribune may be interested in this bit of 

 Prussian statistics : " From the first of October, 1863, to like date 1864, 

 there were slaughtered in Berlin 1,552 horses, the flesh of which was sold at 

 from five to six cents the pound." Some years ago the lamented Geoffrey St. 

 Hilaire, enthusiastic propagator of the sound doctrine of Hippophagy, set out 

 a table at his residence by the Jardin des Plantes with baked, and broiled, 

 and stewed, and toasted, and fried, and boiled, and smoked, and roasted horse 

 meat, and preliminary flesh soup of the same. Doctor Yran, one of a dozen 

 partakers of that generous horsepitality, gave a toothsome account of the ban- ■ 

 quet in the time of it. 



A somewhat similar horsepltable experiment was tried on volunteers, after 

 a lecture on the subject, at the Garden of Acclimation in the Bois dc Boulogne 

 last year. All who have eaten are agreed that, prejudice being set aside, 

 horse-meat is good eating. And there is exclamation of regret over the loss 

 of 160,000 pounds of nutritious horse-meat ; lost to hungry Frenchmen annu- 

 ally by their unreasonable prejudices. Of other meat-victuals, meanwhile, 



