fHOTO-MICfiOGRAPHY. 



27 



Lastly, our medical officers of health may detect various adul- 

 terations in their examination of milk and other articles of food. 

 The adulteration of wheat-flour with potato-starch, or the meal of 

 beans or peas, may be detected by the presence of the different 

 grains of starch belonging to these substances. Alum in bread 

 may be dissolved out in water and then re-crystallised under 

 the microscope, and the presence of chicory and roasted coffee 

 may be detected in adulterated coffee. Among these adultera- 

 tions, I may just mention an ingenious manufacture, by which 

 some Frenchmen recently prepared jelly from the Arachnoidisciis 

 faponicus^ a sea-weed much used to pack up the Chinese and 

 Japanese porcelain, which, being appropriately flavoured and 

 coloured, was palmed off upon the unsuspecting Parisians as 

 the " Finest Fruit-Jelly." But, fortunately, this plant-jelly retained 

 some of the fibrous nature of the plant, and was proved by the 

 microscope to differ in toto from the genuine article. 



I must conclude. Much more might have been added, but I 

 think my readers will allow that I have succeeded in demonstrat- 

 ing the proposition with which I started, namely — the Usefulness 

 OF THE Microscope in Medicine. 



T 



pbotO'^flDicroQrapb^. 



HROUGH the kindness of the Secretary of the Royal Micro- 

 scopical Society, we are enabled to give Fig. 2. 

 a figure of Stein's photo-microgra- 

 phic apparatus, which, though small and 

 simple, is said to answer its purpose com- 

 pletely. It consists of a cone, F, which 

 is inserted into the tube, M, of the micro- 

 scope instead of an eye-piece ; a plate of 

 ground-glass is fixed to the top, and on this 

 the image can be focussed, the observer's 

 head being covered with a black cloth. 

 The ground-glass plate is replaced by the 

 prepared sensitive plate, and the image 

 can then be readily photographed. 



This process, if successful, would certainly involve a much small- 

 er outlay of expense and labour than any other we have yet heard of. 



