Page:Popular Science Monthly Volume 18.djvu/388

374 popular as possible; and it particularly desires to be useful to the physicians, meteorologists, and the commercial manufacturers who have occasion to use fairly accurate thermometers. The testing of illuminating oils, the manufacture of spirits and ethers, and the numerous operations of the chemical laboratory, require thermometers of considerable accuracy, and for the benefit of persons using such the observatory has issued a circular which will be mailed on application.

Thermometers may be sent by mail or express, directed to the Winchester Observatory, New Haven, Connecticut. If they are sent by mail (and nothing larger than a clinical thermometer should be), they ought to be packed in a wooden box, in tissue-paper. In whatever manner they are sent, a little care taken in packing them in soft paper will materially lessen the risk of accident. Ordinary thermometers are returned to the senders, with certificates stating their deviation from the true mercurial standard for every ten degrees, within a few days from the date of their reception. Standards require from a week to a month for their investigation, depending upon the degree of precision desired in the final certificates.

The official circular of the observatory contains detailed information relating to the supervision of hospital thermometers and the facilities offered to makers. There is no good reason why any maker should not furnish, with any thermometer sold, a certificate stating the errors of that particular instrument. That the service will be a popular one is shown by the fact that already about five hundred thermometers have been sent to the observatory for verification, and not the least benefit will be that the errors of every thermometer issued with a certificate will be on file at the observatory, and this will be of particular value in cases where a uniformity of data is desired, as in the case of the United States Signal Service, or the observations made by isolated meteorologists in different parts of the country.

 

UT bile is not the only substance which produces a depressing effect upon the circulation when absorbed into it from the portal system. I have already mentioned that certain albuminous products of intestinal digestion and peptones occasionally make their appearance in the urine. Among the former is an albuminous substance, not precipitated by boiling, but by nitric acid in the cold. This 