ITS MICROSCOPICAL DETECTION. 351 



lowed Vauquelin in assuming that these crystals are phosphate of 

 of lime, but this is obviously impossible, because the latter does 

 not crystallize from organic solutions (and these crystals present no 

 resemblance to apatite either in their form or in the mode of their 

 formation). But independently of this we may readily convince 

 ourselves, both by microscopico-crystallometric and bymicroscopico- 

 chemical analysis, that these are crystals of the ordinary triple 

 phosphate. 



Vauquelin* found 6-g- of organic matter, 3 f of earthy phosphates, 

 and If of soda, and hence altogether 10 J of solid constituents, in 

 the semen. 



With regard to the analysis of the semen, we have merely to 

 follow the rules laid down for the investigation of the animal fluids 

 generally ; in the quantitative analysis we should, however, bear 

 in mind, that by mixing the fresh object with a very dilute solu- 

 tion of ammonia, the separation of the organic matters from the 

 actual fluid of the semen may be prevented, and hence probably a 

 quantitative determination of the spermatozoa and other morpho- 

 logical elements of this secretion may be accomplished by filtra- 

 tion. In order to examine with accuracy the extractive matters 

 of the semen, we should first dilute the fresh fluid with a little 

 water, and neutralize with dilute acetic acid, and then filter, before 

 commencing to evaporate, or to extract the residue with water and 

 alcohol. 



In a medico-legal point of view the examination of the 

 seminal fluid is of great importance. Much attention has recently 

 been paid (by Rernak,f Bayard,! and C. Schrnidt,) to the charac- 

 ters which distinguish seminal fluid on clothes, linen, &c., from other 

 dried fluids, and enable us to detect this secretion with certainty. 

 The form of the spermatozoa is so characteristic, and so different 

 from all other animal or vegetable forms, that on a microscopic 

 examination they cannot be mistaken for any other structures. 

 The diagnosis of semen in animal fluids, as for instance the urine, 

 is extremely facilitated by the comparatively indestructible cha- 

 racter of the animalcules. It is further worthy of notice that I have 

 always found that urine containing semen very readily becomes 

 alkaline, and that even when few animalcules are found, it throws 

 down a mucous sediment of peculiar, finely laminated, and very 



* Ann. de Chim. T. 9, p. 64. 



f Diagnostiche u. pathogen. Unters. Berlin, 1845. S. 148171. 



i Ann. d'Hygiene publique. 1849. No. 43. 



Diagnostik verdach tiger Flecke. Mitan u. Leipzig, 1848. S. 4248. 



