796 SEC. 18. BIOLOGY. 



V. THERMOMETRIC APPARATUS USED IN 

 PHYSIOLOGICAL RESEARCH. 



3745. Clinical Thermometers, made upon Dr. Phillip's 

 principle. Francis Pastorelli. 



The ball and part of the stem are filled with mercury ; above the main 

 column, separated by an air speck, is a small mercurial index ; when heat is 

 applied to the ball the column and index are driven forward ; on cooling the 

 main column only recedes, the index remains, the upper end of which indicates 

 or measures the amount of heat applied. Above the air speck the space is a 

 vacuum. 



3745a. Dr. Clifford Allbutt's Clinical Thermometers; 



Fahr. and Cent, scales ; various patterns. 



Harvey, Reynolds, and Co. 



The general introduction of the thermometer for ascertaining the tempera- 

 ture of the body in disease indicates one of the chief advances in the methods 

 of diagnosis. 



Dr. Aitken used thermometers 10 inches long, and the instrument was 

 hardly met with beyond the wards of a few hospitals. In 1868, Dr. Clifford 

 Allbutt requested Messrs. Harvey, Reynolds, and Co. to make him instru- 

 ments with a chamber anterior to the bulb, reducing the length of the tube 

 from 10 inches to 6 inches, then to 4 inches, and to 3 inches. From that 

 time the use of the clinical thermometer has rapidly extended, until now it is 

 found in the pocket of almost every medical practitioner. 



3745b. Clinical Chart Forms for temperature, &c. 



Harvey, Reynolds, and Co. 



Quarto size for hospitals ; octavo size for medical practitioners and their 

 patients. Designed by Edward Casey, M.D., Windsor. 



3746. Standard Thermometer, for physiological purposes, 

 0-50, divided into T V (Virchow). Geissler $ Son, Berlin. 



3747. Standard Thermometer, for physiological purposes, 

 30-45 (Heidenhain). Geissler $ Son, Berlin. 



3748. Two Pocket Maximum Thermometers, for the use 



of physicians, in a case and ebonite sheath. 



Geissler fy Son, Berlin. 



3749. Geissler's Standard Thermometer, for determining 

 the temperature of the skin, divided into -j^ . 



Geissler fy Son, Berlin. 



3750. Geissler's Standard Thermometer, for determining 

 the temperature of the ear. Geissler fy Son, Berlin. 



3751. BiOsenthal's Electrical Thermometer, for deter- 

 mining animal heat. Constructed by Dr. A. Lessing, of Nurem- 

 berg. Prof. Rosenthal, Erlangen. 



The electro-thermometer consists of a bundle of iron and German silver 

 wires, which is contained in an elastic catheter, and can be easily introduced 



