TRANSACTIONS OF SOCIETIES. 323 



metals, the occurrence of their ores, and the modes of preparing 

 the latter for smelting. About one-half of this part of the book 

 is devoted to fuels, furnaces, and the materials of which these 

 consist. Thus the student is led up to the general principles of 

 metallurgical processes. The next ten chapters are more 

 specialised : four of these are assigned to iron and steel, after 

 which the metallurgy of copper, lead, zinc, tin, silver, gold and 

 mercury is {particularly described. A chapter on alloys and one 

 on the applications of electricity to metallurgy close this second 

 section. Several exercises are appended for laboratory practice. 



MlCROKINBMATOGRAPHY— In a recent issue of Nature 

 (Vol 88, p. 213), illustrations are given of the latest application 

 of the kinematograph, indicating another stage of technical attiain- 

 .ment and another field in which it may .supplement knoiv\'Iedge. 

 This stage has been reached by extending its range so as to re- 

 present objects as seen through high microscopic powers. The 

 objects are seen against a black background, and are lit up by 

 lateral rays. As under these circumstances the bulk of the light 

 rays are deflected from the surface of the object under examina- 

 tion relatively little of its internal structure is seen. Cell nuclei 

 are, nevertheless, frequently quite distinct, and the kineto-nucleus 

 of a trypanosome can be clearly followed in motion. Amongst 

 otlher films prepared is one displaying the blood in actual circu- 

 lation through the vessels of the living body. The action of 

 leucocytes as bod}^ scavengers is also depicted in the surrounding 

 and ingestion oi a diseased red cor])uscle by a white ceil. Another 

 film represents the condition of the 'blood in a case of relapsing 

 fever : long spiral threads dart hither and thither upon t'he screen, 

 imipinging and recoding alternatel}-, now hooking themselves to- 

 gether and then disentangling again, the whole Wood history of 

 such an attack being shown. Not the least important of this 

 aipplication of the kinematograph lies in the fact that some of the 

 actual changes which it depicts take place so rapidly that it is 

 beyond the power of the unaided human retina to follow their 

 sequence, but by reproducing them at a slower rate upon the 

 screen the kinematograph helps us to a clearer perception of the 

 actual nature of the process or alteration which takes place. 



TRANSACTIONS OF SOCIETIES. 



Chemical. ]\If.tali.urgicat. axd Mining Socifty of South Africa. — 

 Saturday. January 20th: Mr. H. A. White, Vice-President, in the chair. — 

 " Some oI)servations on ancient mine workings in the Transvaal " : T. G. 

 Trevor. The author differentiated between ancient and modern work- 

 ings by treating all small workings for copper or iron as modern native 

 (Bantu) workings, and all workings for gold and tin, as well as the 

 copper and iron workings, which are of great extent, as presumably 

 ancient in their origin. The ancient workings arc extremely plentiful in 

 some of the northern districts of the Transvaal, liut extend no further 

 south than the latitude of Pretoria. A general description of the workings 



